The problem of the object of activity in A. N. Leontiev's psychological theory of activity is considered. It is shown that the essence of activity consists not in striving for the object which will satisfy the corresponding need, but in overcoming of the resistance which the subject meets on the way to need satisfaction. The principle that any activity is object-mediated is specified in the article in the following way: the principle consists not in the fact that the means of need satisfaction are objects, but in the fact that the resistance determines the object content of the activity (goals, tools, and means of need satisfaction chosen by the subject) and therefore assigns direction to the activity. The notion of the "image of resistance" is introduced as a basic constituent of the mental reflection of the world. The author also critically reviews some aspects of the theory concerning activity motivation and goal-setting.