Routine and innovative use are the critical enterprise systems (ES) usage behaviors that would significantly affect the extent to which the firm derives benefits from the system in the post-acceptance stage. Yet, our understanding of what motivates these two types of ES use remains limited. Drawing upon transactional-transformational leadership theory, regulatory focus theory and IS literature, we examine how leadership style (i.e., transactional and transformational leadership) and regulatory focus (i.e., prevention and promotion focus) affect employees’ ES use (i.e., routine and innovative use). Specifically, we propose that other than their differentially direct effects, transactional and transformational leadership interact with two regulatory focus differently in affecting routine and innovative use. The research model will be tested by data collected from employees at one of the largest financial service companies in China. Research design and expected contributions of this study are also discussed.