Abstract: This article is divided into three parts: (1) A brief analysis of the formation of A. N. Leontiev's theory of activity in relation to the need for a new system of psychology after the October Revolution and the establishment of the new social institution of USSR, the culturehistory, of the influence of A. N. Leontiev's theory and the early research done by A. N. Leontiev himself; (2) A summary of the basic ideas of this theory, including the meaning of activity as the object of psychological study, the definition of activity, its basic characteristics and types, and the interrelation among activities, their structure, dissociation and combination, etc.; (3) a twopoint evaluation of this theory, affirming its important reference value in establishing a Marxist psychology.

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