Abstract: Abstract : The implementation of Yen loans forestation project has the extremely vital significance to the sustainable development of the project area. Based on the analysis of ecological, economic and social sustainable development, this article create a set of method for the sustainable development of the project area which includes index system and assignment standard. The basic index of this method includes project implementation and policy implementation, ecological, economic, and social four items. And by using this system , Inner Mongolia autonomous region Wu Shen, Yi JinHuoLuoQi, WuYuan and Qing Shuihe were quantitatively analyzed after the Yen loans forestation project. And the results show that: Project implementation and policy implementation index weights 20%, ecological index weights 20%, economy determines social development index weights 30%, the society accounts for 30%. Through the evaluating indicator system of sustainable development of Yi Jin Huo Luo Qi and the four flags county , it shows that YiJinHuoLuoQi has a higher improvement whether in economic, ecological or social benefit , total score is 80.12. Three other flag county also gained remarkable ecological, economic and social benefits, and total score of WuYuanXian, QingShuiHeXian WuShenQi banner were 77.71, 80.12, 74, 79.98. After the evaluation of the regional sustainable development, the result shows that this method is feasible。