The subject-matter of the paper is an analysis and tasks of the socialist type of social development under conditions of the contemporary stage of the development of the Czecho-Slovak society in the context of the economic and global social development. Social development is understood as a relatively independent sectional sphere of the society. The author analyzes especially the intensificational and humanizing-emancipative function of social development and he also points to its integrative function in the society. He considers social subjects, social processes and social relationships to be the core of the sphere of social development. He characterizes social policy as a policy of the social development of man and of his creative activity, and not as a policy of social security fair people only. On the basis of the analysis of social development he draws conclusions for his entire theory and conception.