The Returning Farmland to Forest Project the biggest ecological engineering in China, which brings up great economic and social performance to the afforested area. This paper analyzes the socioeconomic performance of Zhi idan County and Zizhou county in Northern Shaanxi Province before and after returning the farm land to forest,and studies the impacts of the project on grain output, agriculture output value,forestry output value,grassland farming output value and constituent ratio,and per capita income. At the same time,it analyzes the social performance from labor force transferring and peasant consumption expenditure,compares the above changes in the two counties，and provides suggestions on how to maintain the achievementis of the project and regional evelopment in the two counties,and assures healthy development of the project.