中文摘要：

本研究以常州市为例，观察经济社会驱动因子与耕地保护政策作用的机制，研究区域耕地面积变化的驱动力机制中哪些经济社会驱动因子在其中扮演了重要角色，在耕地数量变化过程中耕地保护制度的绩效如何，并从中发现反馈的信息，为下一步政策调整，协调经济发展与耕地保护的矛盾，强化土地政策参与宏观调控的效果提供决策依据。通过经济计量方法和模型检验了常州市人口增长、经济发展水平、农业结构调整、固定资产投资、农副产品价格以及耕地保护制度等经济社会因子在耕地数量变化中的作用。结果表明，人口增长、经济发展水平、农业结构调整、固定资产投资等驱动耕地数量不断减少，而农副产品价格、耕地保护制度的作用相反。且耕地保护制度变迁在不同时期的制度绩效不同，1997年以后的政策比之前的政策在保护耕地的作用更有效一些。中国政府基于现实条件的理性选择应是，实施积极的耕地保护政策，严格耕地保护，加强土地调控。

英文摘要：

Rapid economic development following the reform of 1978 in China has resulted in significant land use and cover change （LUCC）, which is among the most important socio-economic driving forces of national as well as local environmental change. Regional response of Yangtze River Delta to LUCC is one of the most intensive in China, and quantity change in cultivated land is the most remarkable regional response to LUCC. In the course of quantity change of cultivated land, farmland protection policies are very important control tools. The purpose of this paper is to explore which one of socioeconomic driving factors plays the important role in the change of cultivated land quantity in Changzhou City, as a case study of Yangtze River Delta, and to investigate the mechanism of mutual action between socioeconomic driving factors and farmland protection policies, so as to adjust land polices and strengthen macro-control. The relations between variables are estimated through two econometric models： the linear regression model I is about the impacts of agricultural sector restructuring and urban growth, and the linear regression model II is about the impacts of total population, per capita GDP, agricultural sector restructuring, investment in fixed assets and food price on the change of cultivated land quantity. Another important purpose of this paper is to provide variables of institutional changes in farmland protection policies to the two linear regression models. The estimation results show that the change of cultivated land quantity is associated with total population, per capita GDP, agricultural sector restructuring, investment in fixed assets, food price and farmland protection policies. This suggests that total population, per capita GDP, agricultural readjustment are the major reasons for the decrease of cultivated land quantity, while farmland protection policies plays a limited but different role in keeping the balance of cultivated land quantity. The rational choice of Chinese government is to implement po