The determination of the complex--important professional psychological features, which has to respond, at the beginning of the professional training, to the requirements of one of the most popular variety of work on the belt--installation of small details--was performed by examining some functions of the higher nervous system (HNS) and some individual peculiarities in the professionally "successful" and "failures" at different stages of their professional activity. The received statistically significant differences between the polar groups allow us to accept, that on the basis of the capability to master the specialty--fitting of watches stand: Weak nervous system, moderate inertness of the nervous processes. Accuracy of static and dynamic coordination of hands. Expressed social responsibility. Self-control (establishing the standards for control actions, knowledge of signal signs.