The purpose of this study is to examine the influence of a leader's transformational leadership on follower's in-role behavior, organizational citizenship behavior(OCB), and innovative behavior. In addition, we attempt to verify the mediating effect of social identification with the work unit and personal identification with the leader on the relationships between a leader's transformational leadership and in-role behavior, OCB, and innovative behavior. While prior studies have usually tackled the relationship between transformational leadership and follower's in-role behavior, OCB, and innovative behavior, they have rarely examined the mediating effects of social identification and personal identification on these relationships. Based on prior literature, this study derives following hypotheses. H1: Transformational leadership will be positively related to social identification of subordinates. H2: Transformational leadership will be positively related to personal identification of subordinates. H3: Transformational leadership will be positively related to in-role behavior of subordinates. H4: Transformational leadership will be positively related to OCB of subordinates. H5: Transformational leadership will be positively related to innovative behavior of subordinates. H6: Social identification will mediate the relationship between transformational leadership and in-role behavior, OCB, and innovative behavior. H7: Personal identification will mediate the relationship between transformational leadership and in-role behavior, OCB, and innovative behavior. To test the proposed hypotheses in our study, we collected data via a survey on data 300employees in 11 organizations, and after excluding unanswered items questionnaires, total of 213 employees data is used for analysis. Hierarchical regression analysis is used to test the proposed hypotheses. Sobel test is used to test the significance of the mediating effects of social identification and personal identification. The major findings are as follows: First, as predicted, a leader's transformational leadership were positively associated with social identification and personal identification. thus providing evidence that transformational leaders are likely to exert their influence on followers by affecting their feelings of identification. Second, transformational leadership is closely related to in-role behavior, OCB, and innovative behavior. Third, personal identification and social identification have turned out to have a full or partial mediation effect on the relationship between transformation leadership and in-role behavior, between transformation leadership and OCB, and between transformation leadership and innovative behavior. That is, this result indicated that a leader's transformation leadership indirectly effects on in-role behavior, OCB, and innovative behavior through social identification and personal identification. Finally, however, when we entered transformational leadership, personal identification and social identification simultaneously into the equations, social identification fully or partially mediates the relationship between transformational leadership and in-role behavior, OCB and innovative behavior, whereas personal identification only mediates the relationship between transformational leadership and OCBO. Consistent with Kark, Shamir and Chen(2003), results also suggested that different mechanisms (personal or social identification) could, at least partially, account for these different outcomes (in-role behavior, organizational citizenship behavior, and innovative behavior of followers) of transformational leadership. Given the small number of samples, this study constitutes an exploratory attempt in nature. Caution must be exercised in attempting to interpret findings and to generalize the recommendations. The results proposed in this study must be validated by further research in diverse research settings. The results of this study are limited by its cross-sectional design and by the use of a single method of data collection. Causality could not be claimed due to the cross-sectional nature of the data. Longitudinal and experimental designs are needed to settle the dynamic relationships between transformation leadership and in-role behavior, organizational citizenship behavior, and innovative behavior. Additionally, although the hypothesized model was consistent with the data, there may be other, untested variables that might reflect a more complex process than is depicted in our model. For a comprehensive model of transformational leadership, future research must consider other variables, which may have complementary or substitute relationships with personal or social identification. Despite its limitations, the study has made several tentative contributions to the literature on transformational leadership in organizations. In general, the results of the study provide fairly strong support for the hypothesized relationships between transformational leadership,followers’ identification with the leader and the organizational unit, in-role behavior, organizational citizenship behavior, and innovative behavior. Furthermore, support was also found for the hypothesized differential roles of personal and social identification in mediating the relationships between transformational leadership and followers’ in-role behavior, organizational citizenship behavior, and innovative behavior.