On the basis of systematically expounded the concept and intrinsic mechanisms of the integration of industrialization, urbanization and agricultural modernization, we make an empirical test to the integration of industrialization, urbanization and agricultural modernization in Jiangsu. The results show that from 1990to 2011, the upward trend of urbanization and industrialization in Jiangsu Province is obvious, but the decline in the level of agricultural modernization is also obvious. In the process of industrialization, urbanization and agricultural modernization fusion, the most important problem is a mismatch between the development of urbanization and agricultural modernization, as well as industrialization leading role in the development of urbanization is not obvious. Based on this conclusion, the article put forward policy recommendations from the institutional mechanisms. The research results provide a scientific reference to accelerate the transformation and innovation , adhere to the simultaneous development , speed up structural reform for promoting the integrating of industrialization, urbanization and agricultural modernization.