Cognitive activity of a child increases and undergoes qualitative transformation in the preschool age. Each level at that is characterized by different objects: I-directly perceived features of things; II-relations between internal, hidden features and external features; III-completely internal features-ethical estimation concepts. The level of cognitive activity to be found in a particular preschool child is determined by the level of his communication with adults and age-mates. Transition to a higher level of communication with adults results in a higher level of cognitive activity, however at each level this influence is mediated by different processes.