Coupling Mechanism for Building up Harmonious City

In order to realize `win-win´ between economic development and environmental protection, it is necessary to study the coupling mechanism of economic development and environmental protection. The paper builds up the reversible equation and optimum principle of coupling mechanism of economic development and environmental protection, and provides the measure standard. Jilin Province is selected as an example. The quantitative analysis of economic development and environmental protection is based on the sixteen indicators that are representative in 9 cities of Jilin Province. The two main factors - economic development and environmental protection, are screened by factor analysis method, and the coupling mechanism of economic development and environmental protection is assessed. The results show that the development of most cities in Jilin Province is environment and economy lagging status of rudimentary development level, except Changchun City and Jilin City; both are at advanced development stage. On the basis of the assessment, conclusions and suggestions about sustainable development of economy and environment are printed out, and they can be used for reference for subsequent studies.