AbstractGiven its importance to organizational development, interest in exploring the antecedents of employee proactive behavior has grown exponentially. Moving beyond the traditional managerial mindset, we highlight the role of Chinese enterprise union practices in fueling proactive behavior. Drawing on the conservation of resources theory, we argue that Chinese enterprise union practices can exert a downward influence on proactive behavior, and critically, this cross‐level effect can be accounted for through perceived insider status and affective commitment. Multilevel structural equation modeling based on a sample of 433 employees from 43 enterprises supported the hypotheses. This study responds to previous calls for action to commence a multidisciplinary perspective to explore predictors of proactive behavior, and contributes to a deeper understanding of the distinctive characteristics and unique effects of trade unions in China. It also presents implications for broader union research and workplace partnership initiatives aimed at promoting better labor relationships.