Intergroup attitude has always been an important issue in traditional social psychology for its blending of individual and social characteristic, social identity, intergroup threat and group-based emotion were the most relevant and important variables in traditional researches. Though there were many studies have found the basic role of social identity, few studies have tried to integrate those variables in the same model. For example, ITT first tried to argue that the realistic threat, symbolic threat and intergroup anxiety complement each other when affecting intergroup attitude, but it didn’t explore the relation of different threats and different emotions. Other researchers have showed that different threats might work on different attitudes and behaviors through different emotions, or have tried to propose a theory model including the three main factors, but there were rare researches to investigate the hypothesis systemically. Moreover, former studies mainly focused on the attitude to the out-group, neglecting the attitude to the in-group. And the later is also an important part of intergroup attitude. So the present study was aimed to explore the role of social identity, three forms of intergroup threats and three forms of intergroup group-based emotions in effecting the two forms of intergroup attitudes, and systemically analyze the fundamental role of social identity and its potential influencing mechanism. In order to reach the aim, a questionnaire survey in the background of Diaoyu Island Event was carried out, before formal survey, a primary survey including 150 students from the target populate was made, and the result was used to modify the specific questions. In the formal survey, 431 undergraduates from different grades and majors took apart in the research in the unit of class (151boys and 256 girls). A neutral background material of about 1000 words was edited on the news from Sep 7th to Oct 20th, the questionnaire included identity to nation, three types of group-based emotions, three types of intergroup threats, and two types of intergroup attitudes, most of the questions were based on former researches and were modified to the specific situation. The last part of the survey was some demographic data. The date collected was analyzed by SPSS13.0 and SEM. The result showed: firstly, national identity as the main antecedent variable could have a direct effect on both the in-group and out-group attitude, but also have an indirect effect the two intergroup attitudes through cultural threat and anger. But as the structural model showed, it had no significant effect on identity threat, realistic threat, uneasy and depressed. The result verified former researches and hypotheses partly. Secondly, different intergroup threat had varied effect on different intergroup attitudes through different group-based emotions. For example, the effect of identity threat on the in-group attitude was fully mediated by depressed, and the effect of realistic and culture threat on the two intergroup attitudes was partly or fully mediated by anger. Finally, national identity can both mediated the effect of identity threat on the two forms of intergroup attitude and the mediation of anger between identity threat and the two forms of intergroup, and the directions of the two mediations were both negative, which partly suggesting the key role of social identity in effecting intergroup attitude. . Those results proved that the mechanism of in-group and out-group attitude was not all the same, the correlation and difference of them together constituted the panorama of intergroup attitudes.