This article tries to understand the various meanings implied in social policies from the angle of social policy practice in its historical development.It will reveal the origin of the definition of social policy as a plan for social action and welfare philosophy,and explore the basic contents of the theory of social policy studies in its background,goals,contents,nature and belief,as well as methodology.The paper will demonstrate the role of the government,market and the third sector in deciding the nature of social policy or,the distribution of social resources through the history of rise,decline and rise again of the third sector in Europe and America during the century. In view of the fact that there is a difference in perception in decision making and the making of a national social policy,the decision making can only be a process of mutual adjustment and coordination.The social scientists participating in the process need to strengthen the ability of engaging in the spreading of scientific view and methodology,to try their best to be coordinators among all forces.