Abstract: According to the data of Nanchuan Jinfoshan, Yubei Guanyindong, Changshou Longmenqiao water conservancy project’s feasibility study report, with substitution method and shadow price law, the paper researched the variation of regional social stability value after their completion. The results showed that the social stability value of region, in which the water resources project supply for the agricultural irrigation had increased, and Nanchuan district and Yubei district had grown to 262.03 million Yuan and 43.07 million Yuan respectively. Conversely, the social stability value of region, in which the water resources project supply for the urban and industry had reduced, and the social stability value of Changshou district had decreased to 3.22 million Yuan. The bigger the additional irrigation farmland area was, the more the social stability value of cultivated land increased. As one of the important composition of the cultivated land value,the social stability value of cultivated land should be an important indicator for social evaluation, thereby contributing to promote the saving and intensive use of water conservancy project land.