The explanations of the existing theories on the relationship between government and society （hereinafter referred to as “political-social relations”） focus more on the two perspectives of institutional angle and ideological angle，especially on the different modes of political-social relations caused by the insufficiency of institutional supply. On the basis of reviewing these viewpoints，this paper explores a new interpretation framework from the perspective of power angle，and then puts forward the new concept of competence specificity. Based on the study of division of labor in economics，this paper argues that the degree of interdependence between political and social organizations is due to the difference in the competence specificity of social organizations. The stronger the competence specificity of social organizations is，the easier the government and the society form interdependent relationship，and vice versa，the relationship of arbitrary domination is easy to form. This paper takes HIV/AIDS prevention and control as the main field and takes social organizations in Taiwan and mainland China as examples to make a comparative analysis on this issue. The study finds that：the intensive cultivation，specialized staff and volunteers，long-term experience and accumulation of social capital on the basis of division of labor，make the social organizations of HIV/AIDS prevention in Taiwan form a strong competence specificity in their own areas of expertise，which highlights the competitive advantages of social organizations on the one hand，but on the other hand，it also limits the possibility of their cross-regional mobility，and eventually forms the close interdependence between government and social organizations；however，the professional division of social organizations for AIDS prevention in mainland China is not clear，lack of intensive work in the inherent fields，lack of full-time staff，especially the poor professionalism and high mobility of staff and volunteer teams，all kinds of factors make them lack the competence specificity，and they are in an arbitrarily dominated position in collaboration with the government. From the perspective of institution，this paper further explains the reasons for the formation of different competence specificity of social organizations.