This article interprets the implications of “low carbon city” from a sociological perspective, and thinks that low carbon city is not only to update the technical, administrative and development patterns, but also a social structural form. This means a low carbon city has to be realized by adapting the social structural form of a certain city to the development of a low carbon city through the integration of the city society system. This article discusses the key issues and difficulties facing China during the construction of “low carbon cities” are the conflict between the urgent need for economic growth and the realization of low carbon cities, greater sense of speculation of low carbon city than its practical sense, laying particular stress on practice while neglecting rational thinking, the absence of faith and the prevalence of materialism, technical and administrative path dependence, and the polarization of the social class structure. Finally, this article proposes the choice of approach to low carbon city in China, where the goal of “low carbon city” should be realized by focusing on the realization of the forms and relations of government/power, enterprises/market, citizens/society and ideology/culture in the city society system.