Innovation in human resource and organizational management, centered on team-based systems and performance-based personnel systems, has been spreading primarily among large corporations. Labor unions have mounted fierce opposition to these changes. This study analyzed the attitudes of union leaders—who play a decisive role in union decision-making—toward these innovation measures and the factors influencing their attitudes. The study examined which of three perspectives exerts greater influence: social network considerations, agent role considerations, and organizational commitment. A survey of 122 union leaders at the executive (chapter president) level revealed that union leaders more strongly opposed innovation when they perceived greater damage to their social networks as a result. From the agent role perspective, leaders also exhibited negative attitudes when the status and compensation of rank-and-file union members were adversely affected. On the other hand, leaders with strong affective commitment and loyalty toward the company tended to adopt more favorable attitudes toward innovation. Thus, union leaders appear to value their political base while simultaneously possessing both an agent consciousness and a labor-management community consciousness. The study also discussed the theoretical and practical implications of these findings.