Abstract: This paper expounds the development process from the concept of comparatively well-off society to ideal and then to reality, analyzes the relationship between comprehensively building well-off society and realizing socialist modernization, and presents the historical task of ail-roundly building comparatively well-off society in next 20 years. The essence of this task is economic development; the focal point is to solve the problems of agriculture, rural area and peasants; The difficulty lies in the adjustment of social structure, the development of social services and the all-round progress of society.