As an important way in the process of the transformation of social governance system，the government purchase of public services has gradually entered people’s vision. What is the relationship between the government and the social organization in the process？Does it change during the process？The paper studied the possible changes in relationships between government and social organizations during the process of government’s service contracting through four cases in the field of the disabled. The study concludes that：（1）There are three kinds of relationship between government and social organizations in the government purchase：Administrative Attachment，Resource Dependence and Cooperative Partners；（2）The difference of the relationship originates from the interactive condition of the government and social organizations in the process. On the one hand，the differences of professional abilities and the degree of adherence of values and missions have influences on the organizations’ competency to deal with resource，and form different relationship models subsequently. On the other hand，the support from government is also crucial，if there is improper operation，it would be likely to produce the asymmetric dependencies and have the risk of mission deviation in social organizations.