Social services or personal social services are an important component of social policy. The development of social services is an important indicator of social welfare level in a country or a region. In recent years，the authorities in Guangzhou priorities social services development. Much more public fundings has been invested in the area of social services，and a new mechanism of government purchase of social services by social organizations has been established. Along with the growth of social organizations and the development of the professional social workers，it is fair to say that Guangzhou has entered an era of social services expansion. This article aims to give a comprehensive examination of the origins and evolution of social services in Guangzhou city by focusing on the establishement and operation of the mechanism of government purchase of social services from social organizations. Finally，policy suggestions is proposed to improve the social services in Guangzhou.