Possibilities of the human activity approach in psychological research are discussed. The paper states about the necessity of subsequent development of psychological human activity theory: first of all the general structure of human activity is to be specified. Particular importance must be given to diachronic aspect of its structural analysis. The system of essentially different components that constitute its process must be described, and their interdependencies must be revealed. The author emphasizes the significance of the final component of the human activity, i.e. the action of satisfying the initial drive of the subject. Regarding this action as the activity “realization phase” can give the key to the problem of reinforcement. The pair of notions — “orientation” and “execution” — will be of value when solving the problem of set consciousness.