Abstract: Reform and innovation are crucial for organizations to survive and develop in VUCA era. However, it is far from enough to rely on formal and limited change initiatives at the organizational level. The discovery of change opportunities and the implementation of change initiatives require the efforts of every member of the organization. As a change-oriented organizational citizenship behavior, taking charge has received a great deal of attention from scholars and practitioners. Taking charge entails voluntary and constructive efforts, to effect organizationally functional change with respect to how work is executed within the contexts of their jobs, work units, or organizations. Characterized by challenging the status quo rather than maintaining it, taking charge is regarded as an important guarantee for the survival and success of the organization. As a behavior to improve work effectiveness, taking charge has been proven to enhance job performance in previous studies. However, most studies have limited the actors of taking charge behavior to employees or subordinates in the leader-subordinate dyads, and pay less attention to the leader’s taking charge behavior. Besides that, studies on taking charge are mostly focused on the impact of taking charge on individual-level performance, rather than team-level. Therefore, based on the team level, this paper focuses directly on leader's taking charge behavior, to explore the mechanism and boundary conditions of leader taking charge on team performance. Based on the two-wave data from 380 team members and 110 team leaders, we tested the hypotheses using Mplus 7.4. The results showed that leader taking charge increased team performance via the continuous mediating role of team belief and team taking charge. Environmental uncertainty positively moderated the relationship between leader taking charge and team belief, and the indirect relationship between leader taking charge and team performance via team belief and team taking charge. The positive effect of leader taking charge on team belief is stronger and more conducive to motivating team taking charge and improving team performance under high environmental uncertainty. Possible contributions of this study are as follows: firstly, it has enriched the study of taking charge behavior at the team level. By examining the mechanism that promotes team taking charge and team performance, the study promotes the further expansion of taking charge theory. Secondly, it has broadened the research perspective of taking charge. The study directly focuses on the leader taking charge behavior instead of employees or subordinates, providing valuable insights into the role modeling of leader taking charge to team. Finally, it has verified the effect of environmental uncertainty, indicating a boundary condition to show when leader taking charge is more important to sustain team taking charge and performance. The findings of the study provide some reference for the management practice of organizational change and innovation. Leaders should be fully aware that high environmental uncertainty is a good opportunity for change, and that leaders need to take on the responsibility to enhance employees' initiative and creativity by shaping and strengthening their common beliefs about taking charge, so that they can better cope with future risks and challenges.

Key words: taking charge, team belief, environmental uncertainty, team performance, role modeling

摘要： 基于社会学习理论，本研究考察了领导主动变革行为影响团队绩效的内在机制和边界条件。通过对110个团队领导和380名团队成员两阶段配对问卷调查，研究发现：领导主动变革行为依次通过团队主动变革价值信念和团队主动变革行为对团队绩效产生正向影响，环境不确定性正向调节领导主动变革行为与团队主动变革价值信念之间的关系，从而促进团队主动变革行为和提升团队绩效。研究结果有助于推进团队层面主动变革行为研究，同时对组织变革创新的管理实践具有重要意义。

关键词: 主动变革行为, 价值信念, 环境不确定性, 团队绩效, 榜样示范