Fragmentary system of resource value and distorted farmland resource price result in ignoring the latent expense of land resources that have ecological and social values during the farmland non-agricultural conversion.Based on this recognition,this paper analyzes the value loss of social eco-system and the spatial situation during farmland conversion in Jiangsu Province.Results show that the value loss of social eco-system is 9 932.202 million Yuan in Jiangsu Province from 2000 to 2007.Per unit value of farmland social eco-system in the north of the province is bigger than that in the south.