The manual presents the materials of the study of style mechanisms of implementation of the leading managerial function - decision-making functions. The study of individual style of activity is one of the stages of psychological analysis of any activity. At present, it is the management style that is considered as the main determinant of effective management. General-activity management style - integration of functionally dependent stable methods and techniques of organizing the activities of the head in polyvariate management situations . Among the situations that arise in management activities, situations that require decision-making are extremely important. Detailed study of decision-making styles in management activities is carried out from the standpoint of the author's individual typological model .. The manual presents a questionnaire that allows you to diagnose the style of management decision-making, gives a detailed interpretation of each of the styles analyzed. For students studying in the specialty "Organizational psychology and psychology of labor", managers, consultants, teachers of psychological faculties