Drawing on social identity theory, this study provides a model explaining the underlying process through which transformational leadership influences creative behavior and organizational citizenship behaviors. Individual differentiation and group identification are proposed as social identity mechanisms reflecting the characteristics of personal and collective identity orientations that underpin the differential effects of transformational leadership behaviors on performance outcomes. The model is tested with data from a sample of 250 front-line employees and their immediate managers working in five banks in the People's Republic of China. Results of hierarchical linear modeling provide support for the model whereby group-focused and individual-focused transformational leadership behaviors exert differential impacts on individual differentiation and group identification. Furthermore, individual differentiation mediates the relationship between individual-focused transformational leadership and creative behavior, whereas group identification mediates the relationships between group-focused transformational leadership and OCBs toward individuals and groups. Implications for theory and practice are discussed and future research directions are outlined.