Compared with the 4.7 billion years of the formation of the Earth and the existence of the biosphere on Earth for 3.4 billion years, the two or three million years of history of human beings is obviously insignificant, but the impact of human activities on the changes in the Earth and the biosphere is increasing, especially in the last hundred years. The 20th century was not only the most brilliant century of human social and economic development in history, but also the century in which the ecological environment was most damaged. While using the ever-advancing scientific and technological civilization to create a brilliant material civilization, human beings have also paid a high price for their unrestrained exploitation of resource wealth from nature because the exploitation and acquisition of natural resources have greatly exceeded the carrying capacity of natural resources and the carrying capacity of ecosystems. "Over the past decade, traditional linear economic approaches have further led to environmental degradation and catastrophe, costing the world $608 billion – the same as the previous 40 years combined," the United Nations Programme's Global Economic Synthesis Report, released in Paris in 2002. "The latest climate models show that unless resource use is significantly slowed and a circular economy model is implemented, by 2100, 100 years from now, the Earth's temperature will be 6°C higher than it is today, which will inevitably lead to major global environmental problems such as warming, biodiversity loss, land impoverishment, air pollution, extreme water scarcity, reduced food production and the spread of deadly diseases." China is currently in the middle of industrialization, facing not only the historical and practical tasks of social productive forces, enhancing comprehensive national strength and improving the people's living standards, but also some quite serious problems such as a large population base, shortage of resources, environmental pollution, and low level of economic development. Industry has always occupied an absolutely important position in China's national economic development and plays an irreplaceable role in China's economic construction. However, for a long time, in the process of industrial production, due to the overall technical level of the enterprise is not high, the enterprise mainly adopts the traditional linear production mode of "resource-product-discharge waste" characterized by extensive production with a large amount of resources, and the resulting industrial pollution and waste of resources are very serious. According to statistics, at present, the energy consumption of China's 10,000 yuan of GDP is three times that of the United States, six times that of Japan, and 4.5 times that of South Korea; steel consumption is 5.8 times that of the United States and 2.7 times that of Japan; about 100 million tons of sewage are directly discharged into water bodies every day; the water quality of more than half of the country's seven major water systems is polluted, and the economic losses caused by economic construction to the ecological environment are nearly 300 billion yuan; the data also show that industrial pollutants account for 70% of the total pollutant emissions. This phenomenon seriously hinders the sustainable development of social economy and the continuous improvement of human quality of life. Therefore, countries around the world are paying more and more attention to the ecological and environmental problems brought about by the rapid development of industry. In particular, at the United Nations Conference on Environment and Development, held in Rio de Janeiro, Brazil, in June 1992, the countries of the world adopted the Rio Declaration on Environment and Development and Agenda 21, the two programmatic documents and the Statement of Principles on Forests, and signed the Framework Convention on Climate Change and the Convention on Biological Diversity. These documents fully embody the new thinking of sustainable development of human society today, reflect the global consensus and the highest level of political commitment on cooperation in the field of environment and development, and play a positive role in promoting the coordinated development of the global economy and population, resources and environment. Regarding the transformation of China's economic growth mode and development model, General Secretary Hu Jintao clearly put forward: "We must accelerate the transformation of economic growth mode, and run the development concept of circular economy into regional economic development, urban and rural construction and product production, so that resources can be used most effectively." Minimize waste emissions and gradually bring the ecology into a virtuous circle. To this end, the National Development and Reform Commission clearly proposed that circular economy should not only become an important part of the "Eleventh Five-Year Plan" overall plan, but also use the concept of circular economy to guide the sub-plans in the "Eleventh Five-Year Plan", for example, China clearly requires in the "Eleventh Five-Year Plan" development plan outline: during the "Eleventh Five-Year Plan" period, energy consumption per unit of GDP should be reduced by about 20%, and the total amount of major pollutant emissions should be reduced by 10%. This is a major measure to implement the Scientific Outlook on Development and build a harmonious socialist society; It is an inevitable choice for building a resource-saving and environment-friendly society; It is the only way to promote economic restructuring and transform the mode of economic growth; It is an inevitable requirement for safeguarding the long-term interests of the Chinese nation. The most widely accepted definition of sustainable development strategy is given by the Bruntland Commission, which argues that "sustainable development refers to development that meets the needs of present generations without compromising the ability of future generations to meet their own needs." The circular economy is the embodiment of this strategy. In fact, the main area for the development of circular economy is the industrial system, and the one-way linear economic mode of industrial production must be gradually changed to the development model of circular economy. The development of ecological industrial system will effectively promote the change of the existing economic development model, because ecological industry is an industrial ecosystem established in accordance with the principles and laws of natural ecology, which requires the efficient combination of material and energy, and coordinates with natural ecology, does not constitute environmental hazards, and is a feedback flow circular economy of "resources-products-renewable resources" with low extraction, high utilization and low emissions. The germination of ecological industry appeared in the sixties and seventies of the 20th century, and was re-proposed in the early 90s of the 20th century, especially in the article "Sustainable Industrial Development Strategy" published in the special issue of Scientific American in September 1989, the concept of "ecological industry" was proposed: "In the traditional industrial system, each manufacturing process is independent of other processes, and the products to be sold and the corresponding waste are produced by consuming raw materials; We can replace this simplistic traditional production method with a more integrated production method, that is, the industrial ecosystem. "The theoretical basis of ecological industry is industrial ecology, that is, a multi-level, multi-structure, multi-functional integrated industrial production system established and developed by applying modern science and technology to imitate the material cycle of natural ecological processes, change industrial excreta as raw materials, and realize circular production and intensive management. Ecological industry pursues the material cycle of each production process in the system from raw materials, intermediate products, waste to products, so as to achieve the optimal utilization of resources, energy and investment. Eco-industrial parks are a practical application of industrial ecology and an effective way to develop a circular economy. It is a new type of industrial park designed and established according to the concept of circular economy, the principle of industrial ecology and the requirements of cleaner production. It connects different factories or enterprises through logistics or energy flow transmission, forms an industrial symbiotic combination of shared resources and exchange by-products, establishes a "producer-consumer-decomposer" material cycle mode, makes the waste or by-products of one factory become the raw material or energy of another factory, and seeks a closed-loop cycle of materials, multi-level utilization of energy and minimization of waste generation. The exchange of by-products between enterprises in the park is one of the most commonly used strategies when applying industrial ecology. At present, all kinds of industrial parks at all levels in China are developing very rapidly, and their status and contributions in economic development are becoming increasingly prominent, so the research and construction of the circular economy development of industrial parks is a specific topic from actual needs, which has great theoretical and practical significance. An effective way for industrial parks to achieve a circular economy is the construction of an ecological industrial system inside and outside the park. The purpose of this book is to provide theoretical and practical guidance for the construction of eco-industrial parks, and to provide scientific basis for project decision-making, operation evaluation and acceptance for the construction of eco-industrial parks. For this reason, this book focuses on the weak links of relevant research at home and abroad, and conducts research on the mechanism of industrial symbiosis, industrial symbiosis model, industrial symbiosis enterprise cluster and analysis of inter-enterprise relationship under circular economy, and pays attention to the connection and correlation between contents. After that, the author proposed the new concept of "industrial symbiotic efficiency", and studied and analyzed the formula definition, connotation analysis and influencing factors of industrial symbiosis efficiency. In the research process, the relevant methods such as industrial ecology theory, ecological industrial park theory, industrial cluster theory, input-output theory and environmental cost (cost) benefit analysis are comprehensively used to carry out normative research. At present, the research perspective of symbiosis mode is basically divided into four categories: First, from the perspective of the behavior mode of enterprise symbiosis, the symbiotic mode can be divided into four situations: parasitic, partial benefit, asymmetric reciprocal symbiosis and symmetric reciprocal symbiosis, of which the latter two can be collectively called mutual benefit symbiosis. Second, from the perspective of the degree of organization, the symbiosis mode can be divided into four types: point symbiosis, intermittent symbiosis, continuous symbiosis and integrated symbiosis. The third is to combine the behavior mode of enterprise symbiosis and the degree of organization, and there are 16 theoretical models of enterprise symbiosis. However, the basic model of industrial symbiosis is the enterprise symbiosis model of reciprocal continuous symbiosis, which is formed on the basis of equal status of enterprises and is a rational choice model for symbiotic enterprises in ecological industrial parks. The key is to cultivate the enterprise into a symbiotic unit with independent status. Fourth, from the perspective of the operation mode of industrial symbiotic network, the symbiotic mode can be divided into four types: dependent symbiotic network, equal symbiotic network, nested symbiotic network and virtual symbiotic network. Different from the above perspective, this study combines the principles of circular economy with the research of supply chain and modern logistics, and proposes and analyzes two specific modes of enterprise industrial symbiosis and their implementation, that is, the construction of enterprise symbiosis system through reverse logistics and green supply chain organization and management. From the perspective of enterprise cluster and industrial correlation theory (industrial ripple effect), the development of eco-industrial parks based on enterprise cluster orientation is studied, and the industrial selection of enterprise clusters in eco-industrial parks, the enterprise cluster effect of industrial symbiosis in eco-industrial parks, and the organizational structure of enterprise clusters in eco-industrial parks are analyzed. From the perspective of enterprise relations, the analysis of corporate behavior under circular economy and the mechanism of inter-enterprise relationship operation under circular economy was carried out. In order to improve the evaluation index system guiding the planning and construction of eco-industrial parks, the concept of industrial symbiosis efficiency was defined and relevant research was carried out. According to the 3R principle, systematic principle, dynamic principle, scientific principle and operability principle, the evaluation index system of eco-industrial parks can be decomposed into four types of indicators: economic indicators, ecological environment indicators, ecological network indicators and management indicators [7]. The research on ISE is one of the important contents of the research and construction of ecological industrial parks, which can be said to be a comprehensive indicator for guiding and evaluating the planning and construction of ecological industrial parks, which has both economic and ecological environment requirements and the construction and management of ecological industrial symbiotic systems. It emphasizes the construction of symbiotic relationships between enterprises and the evaluation of symbiotic effects. This part of the research content is intended to provide some supplement and support for improving the indicator system of ecological industrial parks and improving the guidance and application effect in practical work. On the basis of the above normative research, corresponding empirical research is carried out. Especially based on the actual situation of Jiangxi Province, through field research and analysis, the development of Jiangxi circular economy and ecological industrial park was mainly studied. At the same time, in view of the problem of industrial symbiosis, corresponding countermeasures research was also carried out, corresponding countermeasures for the construction and development of eco-industrial parks were proposed, targeted suggestions were provided for the government to formulate relevant policies of the park, and decision-making basis and reference for park managers and operators to take corresponding measures. The main project basis of this book is "Research on Sustainable Development Model of Circular Economy and Eco-industry in Jiangxi Province" (2004 Humanities and Social Sciences Research Project of Jiangxi Province General Universities) and "Research on the Construction of Jiangxi Industrial Park Based on Circular Economy" (2006 Jiangxi Provincial Social Science Planning Project). Through investigation, the research group unanimously agreed that circular economy, clean production and industrial ecology, that is, ecological industry, are all impacts and breakthroughs on traditional environmental protection concepts, and they have both commonalities and clear theories, practices and operation methods. The circular economy takes the "3Rs" as the basic code of conduct, ecological industry as the development carrier, and cleaner production as an important means, all of which aim to achieve the effective use of material resources and the sustainable development of economy and ecology. The similarities and differences between them can be summarized as: First, cleaner production and ecological industrial parks follow the 3R principles of circular economy - "Reduce, Reuse and Recycle", through the source reduction of individual enterprises and the exchange of by-products and waste between enterprises, the gradual utilization of energy and wastewater, and the sharing of infrastructure to achieve the coordinated development of economic, social and environmental benefits of the park. Second, the compatibility between ecological industry and cleaner production: (1) Industrial ecology originated from cleaner production and is a new stage in the development of cleaner production. (2) There are similarities in promoting the reduction of pollutant emissions and the use of life cycle analysis methods and eco-efficient design, but cleaner production focuses more on requiring enterprises to reduce the use and discharge of toxic substances. (3) The symbiosis between enterprises is a supplement to the enterprise-centered cleaner production, and through the exchange and use of different materials, pollution or waste can be reduced, which contributes to the ultimate goal of zero waste pursued by cleaner production. The difference between ecological industry and cleaner production: (1) The scope of operation is different, cleaner production is concentrated in a single enterprise, while industrial ecology focuses on the symbiotic mode and symbiotic efficiency between enterprises within the scope of all enterprises in the park. (2) The central role of the government is relatively obvious in the implementation of cleaner production, and because the ecological industry uses static means to lock enterprise activities together, it has formed a situation of excessive interdependence among some enterprises, and is not conducive to technological innovation and pollution prevention. (3) The biggest incompatibility is their impact on recycling, material efficiency and risk reduction, for example, cleaner production aims to prevent the generation and recycling of pollutants and hazards, while eco-industry is more driven by the pursuit of material and energy optimization and other economic efficiencies, not to minimize pollutants and hazards, but to encourage recycling within a closed-loop system so that harmful and toxic substances end up in the waste stream. Third, the classic cleaner production extends environmental protection to all aspects related to the organization within a single organization, while ecological industry extends the concept and connotation of environmental protection between various enterprises in the enterprise cluster. Compared with ecological industry, circular economy introduces environmental protection into the economic operation mechanism from the height and breadth of the national economy. Fourth, according to the requirements of sustainable development strategy, specific circular economic activities are mainly reflected in the three levels of enterprises, enterprise communities and society. At the enterprise level, enterprises are required to reduce the material usage of products and services, reduce the energy use of products and services, reduce toxic substances, strengthen the cycle of substances, maximize the sustainable use of renewable resources, improve the durability of products, and improve the service intensity of products. This level is more about cleaner production. At the enterprise community level, it is required to establish the input-output relationship of by-products or waste between enterprises according to the principles of industrial ecology. At the social level, the implementation of harmlessness, reduction and resource utilization of waste, that is, the implementation of material and energy cycles during and after production, consumption, and processes. It is more of a circular economy strategic idea. Fifth, in order to achieve the purpose of ecological industry, it is necessary to shift industrial production from extensive to clean production. The basic spirit of cleaner production is source reduction, and the premise and essence of ecological industry and circular economy is cleaner production. The theoretical basis for this argument is ecoefficiency. Eco-efficiency pursues the maximization of material and energy efficiency and the minimization of waste production, unnecessary reuse means that the efficiency of upstream process material and energy utilization is not maximized, and waste reuse and recycling often consume other resources, and waste once generated, it poses a threat to the environment. This can also be understood from a general point of view, because although the main practice of ecological industry is to use the waste of upstream enterprises as raw materials and energy for downstream enterprises, this does not mean that upstream enterprises can produce whatever waste they want to produce, and discharge as much as they want. Similarly, downstream enterprises cannot use their waste without having to discharge more pollution, but must reduce sources throughout the entire process of their production. In other words, every link in the system must be reduced to achieve cleaner production. That is, the production of producers, the consumption of consumers and the regeneration of regenerators in the ecological industrial system are variable and should be changed in accordance with the principle of cleaner production. The writing of this book has received strong support and help from the Jiangxi Provincial Social Science Planning Office and the key research base of humanities and social sciences of the Ministry of Education "Nanchang University Central China Economic Development Research Center". Due to the level and time constraints, it is inevitable that there will be omissions and inadequacies in the book, and I urge readers to correct them.