A. N. Leont'ev's concept of activity development at .Moscow University Psychology Department for the last 15 years is analysed. The notion of "world image" presented by Leont'ev in his late works and used by his followers enables one to broaden the potentialities of the concept and to use it not only for genetic approach but functional one as well. The notions of need, motive, sense, volition, experience acquire new facets in this context. The author substantiates the inpossibility to use general psychological theory of activity for adequate analysis of interpersonal relations and communications because of activity's subject-object nature.