Since 2003 the rapid development of China's social policy has aroused much academic interest. This research places the development of social policy in China's political and economic context, focusing on the changing role of the state in making and implementing social policy. Based on the policy paradigm theory, this article builds up a framework to analyse the shift of social policy paradigms in post-Mao China, examining the changing role of the Chinese state in social welfare and social development. It argues that China's latest round of social policy expansion was driven by the social problems accumulated during the economic reforms, with change triggered by the SARS crisis, and its shape finally determined by the central political leadership led by Hu Jintao and Wen Jiabao in a top-down manner.