This study investigates the relationship between extrinsic, intrinsic and social rewards, and the organizational commitment of 6,911 employees who work for 13 Japanese companies in Thailand. Hierarchical regression analysis revealed that variables included to measure extrinsic, social and intrinsic rewards were strongly related to organizational commitment. These findings suggest that the antecedents of organizational commitment in the Japanese companies in Thailand are different from those in the other kind of corporations in the West. The comparison between University graduates and others showed that benefit satisfaction and fatigue had stronger and supervisor support and role clarity had weaker influence on organizational commitment in university graduates than in others. Discussions and implications concerning human resource management of Japanese companies in Thailand are offered.