中文摘要：

长江三角洲经济发达地区与中部地区在人均GDP、财政收入、人均农民可支配收入等方面存在较大差距。失地农民社会保障、留地安置、股份合作制等模式及其差异的比较分析表明．这些制度变迁中的经济和政府行为有其内在基础，应将社会保障成本纳入征地成本。考虑地方经济水平，社会保障低标准起步，谨慎运用留地安置政策和谨慎鼓励股份合作制发展并采取多极化的补偿方式，让农民分享社会发展的成果。

英文摘要：

Compared to region of central China, the GDP per capital 、finance income per capital、farmer＇s disposable income per capital of developed region in Yangze river delta areas are tremendously higher. After analyzing the policies of land- expropriated farmer＇s social security, compensation by returning exploitation land, the joint stock cooperative system, and their running mode and differences, it goes further to analyze the economic and government behavior foundation within these institutions and policies. Based on the real condition of the region in central China., it puts forward that it is necessary to bring the cost of social security into the total cost of land requisition. Considering local economic statues, it is essential to low social security threshold for farmers who have lost land, and the policy of returing exploitation land to land-requisitioned farmers should be cautiously implement, besides, joint-stock-cooperative system should be cautiously encouraged. Various methods to compensate farmers should be taken so that they can share the benefit of social development.