中文摘要：

在界定农地边际化的本质及其诊断标准的基础上，利用1980～2002年的全国农产品成本收益数据，以稻谷、小麦与玉米生产的平均状况为例，对中国农地边际化现象进行了宏观层次的诊断研究。结果表明：近20多年来，在我国农地利用过程中出现过“一次边际化迹象与两次明显的边际化现象”。农地边际化迹象出现在1987年前后，但持续时间短、程度轻，农地“边际化”特征不明显；第一次明显的农地边际化现象出现在1991年前后，第二次发生在1996年以后，后一次边际化现象范围更广、程度更重。我国农地利用过程中集约度的显著下降、播种面积的明显缩小以及严重的农地弃耕撂荒现象均与农地边际化的作用密切相关。用农地边际化理论可以较好地解释近20多年来中国农地利用过程中发生的主要变化。

英文摘要：

The history of the land use of many developed countries shows that the courses of industrialization of economy and urbanization of population are usually accompanied by marginalization of agricultural land use. China is now in a developing stage with rapid industrialization and urbanization, and changes such as ＂the more rapid non-agriculturalization of agricultural land, the continuous loss of farmland, abandonment of arable land, the substantial loss of labor force sources from rural areas, the shrinkage of agriculture in the eastern littoral, etc. ＂ has occurred in the process of agricultural land use in recent years. Many scholars have studied these changes and their driving forces, mostly adopting a correlation analysis in statistics. These researches encourltered a lot of criticism, deeper analyses of the mechanism are called, but little progress has been made. So seeking a new synthetical research approach is especially important. This paper firstly defined the essence of the marginalisation of arable land and its criterion to diagnose. Then, based on the cost-income data of three kinds of grain crops such as paddy, wheat and maize during the period 1980-2002, this paper diagnosed the marginalisation phenomena of cultivated land use in China. The results show that there were once suspicious marginalisation evidence and two times obvious marginalisation phenomena of the cultivated land utilization in the last two decades in China. The suspicious evidence only had a faint trace in 1987, and the first and the second ones were in evidence in 1991 and 1996, but the second one was wider and more serious. The marked decline of the degree of intensity of the cultivated land use, the notable shrinkage of the sown area of the grain crops and the severe abandonment of the cultivated land had causal relations with the action of the margilisation of arable land. Theory of the marginalisation of arable land use is useful to explain the changes of arable land use in China.