Along with the implementation of reform and open up policy in China, Jiangsu and Zhejiang, two provinces have got rapid economic development and greatly contributed to China’s market transition. Jiangsu, Zhejiang together with Shanghai, have shaped China’s economic heartland—the Yangtze River Delta Economic Region. Undoubtedly, the private sector is the driving force for the tremendous economic development in the Yangtze River Delta, particularly for facilitating institutional transition and economic development. Fortunately, this kind of economic development driven by the private sector was not only restricted in the Yangtze River Delta Region, but also across the country as it has been gradually extended nationwide. This paper is to look at the development of the private sector in Jiangsu and Zhejiang areas and particularly trace its fantastic effects on nationwide economic development and market transition.