Abstract: The research on newcomer’s organizational socialization (OS) has been criticized for lacking a fundamental theoretical basis, thereby imitating the method of how to measure OS effect. Role Identity Theory and Social Identity Theory can provide OS research a substantial theoretical basis. Based on the theoretical discussion on the boundaries of OS concept, the identity nature of OS was explored as a newcomers’ role identity and social identity development process. The identity theory also revealed two dimensions of OS effect. The content of each dimension was further discussed. Future efforts are expected to develop new OS scale and conceptual model on the basis of identity theory. The identity theory also implies the advancement of research methodology in the future OS study.

Key words: newcomer, organizational socialization, role identity, social identity, construct