This paper investigates the impact of leader feedback on followers’ knowledge-sharing behavior through a regulatory focus theory perspective. Data were collected through an experiment with 129 college students. Results showed that compared with leader’s prevention feedback style and negative feedback valence, promotion style and positive feedback valence inspire employee knowledge-sharing behavior better. These two positive relationships are mediated by promotion situational regulatory focus. The negative relationship between prevention leader feedback style and knowledge sharing is mediated by prevention situational regulatory focus, while negative leader feedback valence has its negative effect on knowledge sharing directly.