Most of the existing “experimentation under hierarchy” literature investigates what drives the diffusion of policy innovation in China at the local level, emphasizing the leading role that the central government has played. However, what happened after the diffusion of a policy innovation to a new locality in the Chinese context – especially, how a diffused policy innovation has been implemented by the local government – has been largely neglected by the existing research. To fill this gap, this study conceptualizes the implementation process of a diffused policy innovation as a process of policy reinvention, and aims to understand this process in the Chinese context at the local level, through a case study of Hangzhou’s car ownership restriction policy (xianpailing 限牌令). This study illustrates that the policy reinvention process in the case of Hangzhou is a political process which is mainly driven by an informal and non-institutionalized learning process dominated by local authorities and an adaptation process centred on how to make a diffused policy innovation politically acceptable and palatable to both the local public’s interests and the national policies and priorities. It also highlights that Chinese local governments do not simply replicate other localities’ policy innovation, but play the key role in altering and shaping a diffused policy to fit local political, institutional and social conditions, although there is no direct mandate from the centre. The significance of this study is that it uses the concept of policy reinvention as an alternative way of studying policy innovation and diffusion in China.