Abstract: The contradiction of form and content which is a source of development, finds the reflection in opposition of stadial and mechanism representations of the processes of professional formation and personality development. For the assessment of the nature of the relationship between these representation features of stadial divisions of these processes are analysed and the types of mechanisms regulating them have been considered. The social adaption and personal initiative approaches to the studies of these processes which are the two mutual complementing views of the mechanisms of the similar aspects regulating their processes are being determined. It is supposed that the last serve as external and internal demonstration of a uniform transstadial mechanism determining all the processes of professional formation and development which represents the update and disactualization (gradual exhaustion) of professional personality potentials.