中文摘要：

基于南通市1978—2008年的社会经济统计数据,计算南通市历年农业结构变化率、农业结构相似系数和农业部门比较优势度.按照农业结构系数与政府调控政策、人均GDP以及农民人均纯收入的关系,将南通市农业结构演变划分为自由演变、计划演变和主动演变3个发展阶段;通过对相似系数和比较优势度的分析比较,发现南通市农业结构演变呈现趋异性,各县市（区）重点发展了本地优势的农业部门.结合资源条件、产业基础、技术条件、市场意识的空间差异对各县市（区）农业发展演变进行分析,为南通市、苏中地区和江苏沿海地区农业未来发展及布局优化提供参考.

英文摘要：

Based on the social and economic statistical data from 1978 to 2008, agricultural structure coefficient, the similar coefficient and the comparative advantage degree of each year are counted. According to the relationship between agricultural structure coefficient and government regulation policies, per capita GDP and per capita net income of farmers, the development of agricultural structure falls into three stages. With the similar coefficient and the com- parative advantage degree, Agricultural structure development is found with divergence and agriculture departments with greater advantages are developed by different counties. Analysis is made based on the space differences of re- source conditions, industrial foundation, the technology conditions and market consciousness aspects. Important references are provided to the agriculture of Nantong, the middle region and coastal areas of Jiangsu province for the future development direction and the spatial distribution.