Although there is an increasing concern about the issue of identity in the organization and management, how individuals socially construct their identities through the influences of internal and external contexts has been neglected. Drawing on previous research proposing that there are multiple levels of self-identities, this study focuses on relational and collective identities, and examines how different identities are constructed in the organization. Using sample of 278 Japanese employees working in Chugoku region, results indicate that effective organizational training could contribute to both relational and collective identity construction through prosocial and intrinsic motivations. Furthermore, environmental dynamism moderates the influences of training on relational and collective identities construction through prosocial motivation. These findings suggest that work motivation is an important mediator in understanding how individuals construct and construe and their self-identity in the organization. Further practical and theoretical implications are discussed in terms of how to apply the results to the business management and how to push forward the identity management theory in the future.