Abstract: Proactive work behaviors, which are crucial for the long term development of the organization, have become a hot topic in organizational behavior research field. However, prior studies indicated that followers’ proactive work behaviors may exert mixed-blessing effect on their leaders, such that followers' proactive work behaviors sometimes triggered their leaders’ positive evaluation whereas sometimes evoked their leaders’ negative treatment. To reconcile these paradoxical findings, this paper draws upon implicit followership theory to propose that whether proactive followers evoke their leaders’ positive or negative reaction depends on the leaders’ proactivity-specific implicit followership (PSIF), i.e., the extent to which leaders assume a follower in general should hold proactive behavioral characteristics. This study first discussed the definition and measurement of PSIF, and then illustrated how the congruence level between follower proactive work behavior and leader PSIF shapes leaders’ behaviors and identified the mediating role of leader core emotions. Overall, our theoretical model seeks to reconcile the mixed results stemming from prior studies and provide insights into how to engage in proactive behaviors wisely for practitioners.