Studies of intergroup conflict in social psychology were reviewed and discussed. Intergroup conflict was examined through three perspectives which focus on the concept of group. The first perspective was "formation of ingroups", and examined the effect of ingroup identification and intragroup processes between ingroup members. The second perspective, "perception of outgroups", discussed how the outgroup is recognized as an opponent in intergroup conflict, resulting in aggression or discrimination against them. The third perspective, "interaction between ingroup and outgroup", explained escalation of conflict in intergroup interaction. Finally, the three perspectives were integrated, and future directives of intergroup conflict studies in social psychology were discussed.