Abstract: With the development of the explorations and practices of the government purchase services,it becomes not only a kind of the transformation of the government functions,but the mechanism innovation of the social governance.Government purchase services deal with the social welfare,social organizations, social work and social standards.The mechanism formation expresses in culturing social organizations, introduction of social work,promotions of social advocacy,and public participations into the social governance.The analysis and the understanding of the restraint factors of the government purchase services are beneficial to the sound and sustained development in the near future and in the long term.