Abstract: The perception of farmers to eco-economic effects after their participating in government leading ecological construction projects is fundamental to their decision whether to continue or adjust their participation behavior and mentality in the future. Revealing farmers' perception to eco-economic effects is decisive to whether future ecological construction will succeed or not. The comprehensive control of mountain, river and lake is one of the typical government leading ecological construction projects in Mountain-River-Lake of Jiangxi. The objective of this study was to interview the perception of farmers to eco-economic effects after their participating in government leading ecological construction projects on Mountain-River-Lake of Jiangxi by the method of Participatory Rural Appraisal. And farmers understanding obtained by interviewing was analyzed with the help of ecological limit method, EXCEL statistics and existing scientific findings. The results showed: 1) The perception of farmers' economic effect emphasized themselves investment, creating and sharing on mountainous aforestation in Mountain- River-Lake area. The farmer possessed usually hematopoietic function after they obtained expected return in the process of participation in ecological construction. Certainly, their dependence on local government presented a decrease to a certain degree. 2) The perception of farmers' ecological effect after participating in presented mainly the reduction of soil and water loss, and the increase of mountain spring water in Mountain-River-Lake area. These reactions of the first ecological effect often concerned whether their production and livelihood safety will be harmed. 3) Derivative effect of farmers' participation income mostly involved production stability, living comfortableness in Mountain-River-Lake area. And it more emphasized on ecoeconomic effect of derivative, showing the large random characteristics. 4) Active improvement was the main pattern of the effect perception of farmers in Mountain-River-Lake area. Future appropriate adaptive policy formulation can stimulate farmers' participation initiative, only considering the farmers' ecological construction function. Therefore, the initiative improvement was the main characteristics of the perception of farmers to eco- economic effects after their participating in government leading ecological construction projects on Mountain-River- Lake of Jiangxi. The behavior of farmers participating in the ecological construction was relatively more initiative, comparing to that of ecological immigration. And it was more easily adjusted by government. The policy implication of this finding will be favorable to provide adaptive policy adjustment paths and scientific basis for government leading ecological construction projects from the perspective of the perception of farmers to eco-economic effects after their participating in.