Scholars have focused on exploration concerning issues affecting innovative behavior (IB). Of previous research finding reviews, transformational leadership (TL) is seen as the most influential factor to promote IB in the organization. TL helps followers to have a unique opportunity to develop learning competence and cooperation in improving IB. Besides, knowledge sharing (KS) is also supposed as the main trigger to build IB. Therefore, this study aims to analyze the mediating role of KS in the relationship between TL and IB. 210 postgraduate students in Indonesian private university are determined as samples. Multiple regression analysis by using SPSS software is applied to analyze the data. The results show that TL significantly affects KS and IB. KS further mediates the relationship between TL and IB.