Abstract: Social identity theory, developed by Tajfel and Turner et al.，which made new explanations to the group behavior， has become the most influential theory in the field of intergroup relation. The social identity theory developed from the explanations for intergroup behavior, it proposed that group identity is the fundamental cause of intergroup behavior. Recent research provides much evidence for the theory, The social identity theory is important achievement of European psychology localization and has important contributions to the social psychology. At the same time it also waits for further consummates

Key words: ethnoentrism, social identity, self-categorization, social comparison, positive distinctiveness