Present-day views on the concept of temperament have been theoretically reviewed. Its specific features distinguishing it from such close psychological concepts as character and personality are presented. Some biological bases of temperament are discussed, and criteria by which a psychological phenomenon should be regarded as pertaining to temperament are given. A new approach to the problem of temperament formation is formulated where it is said that temperament is being developed in the process of generalization of psychophysiological properties underlying psychological activities which goes on indepedently of specific motives, goals, etc. and which is made posible because of the stable nature of all biological structures (individual-neurophysiological included) involved in such activities. It is shown that temperament does not exist either before or after activity - it is developed in the very process of activity.