This study aimed to identify the effect of Transformational Leadership Style on Organizational Citizenship Behavior (OCB), of the Employees in Syrian commercial bank in Damascus. This study has been testing hypotheses from the viewpoint of employees in the Commercial Bank of Syria. To achieve the objectives of this study, were prepared a questionnaire, in order to collect primary data from the research sample, and after ascertaining the validity of the study tools and internal consistency of the words of the variables, were tested the hypotheses, using the SPSS program. This study concluded by a number of results: A weak positive impact of Transformational leadership style on the organizational citizenship behavior. A weak positive impact of (Leader Personality) on the organizational citizenship behavior. A very weak positive impact of (Inspirational Motivation) on the organizational citizenship behavior. A very weak positive impact of (The privacy of relationship between leader and employee) on the organizational citizenship behavior.