Abstract: Sticking to socialism,first,we should make it clear that "What is socialism,and how to build socialism."Deng Xiaoping made a scientific summary of socialist essence on the basis of summarzing the experiences and lessons of Mao Zhedong’s exploration of Chinese socialist construction.He put the liberation and development the productive forces as the essential material base of socialist essence.He put the wiping out the exploitation and polarization as the main principle of socialism.Deng Xiaoping initially and systematically answered the question of “What is socialism‚ and how to build socialism”． He initiated the theory of building socialism with Chinese characteristics．