Abstract: Abstract:Cultivated land is an important natural resource. it plays an important role in promoting urbanization and industrialization of chang-zhu-tan city cluster(CZT), cultiviland resources security has become a necessary choice and a breakthrough path to a two-oriented society (a resource conserving and environment friendly society).With a evaluation index system has been set up to research the security of regional cultivated land resource from aspects such as resource conservation and friendly environment. At the same time, qualitatively describing the security of cultivated land resources, this article has systematically proposed the technical system and AHP and diagnosis of obstacles research method about the security of regional cultivated land resource.the conclusions are as follows:(1)Cultivated land resources security includes quantity security, quality security, and ecological security, which are integrated as a cultivated resources security system; (2)the security trend of cultivated land resources security varies in overall,quantity,quality and ecology aspect, the cultivated land resources security level of Chang-Zhu-Tan city cluster has wholly been declining from 1990-2007, which means that the overall situation of cultivated land resources security in Chang-Zhu-Tan was worrisome;(3)The obstacle factors influencing the security are different in the research period: at the beginning of the period is improper economic development, population increase and urbanization level etc, the influent factors of middle stage are low farmer per captia net income and per capita cultivated land output, and the factors of last phase are excess pollutants emissions ect.