Abstract: [Purpose/Significance] From the perspective of social network circles group polarization, this paper explores the heterogeneity of network circle groups led by different types of opinion leaders, aiming to provide theoretical references and decision support for public opinion management departments in implementing diverse governance strategies to address the phenomenon of group polarization.[Design/Methodology] Taking Weibo platform as an example, this study obtained the data of public opinion events, and used multiple regression models to analyze the relationship between opinion leaders in different network circles and the polarization of public opinion and group polarization of the network circles. [Findings/Conclusion] In terms of group opinion polarization, if the opinion leader is an individual user, the degree of difference between the emotional attitude of group users and the opinion leader significantly impacts the degree of group opinion polarization negatively. Conversely, when official organization users act as opinion leaders, the degree of difference between the emotional attitude of network group users and the opinion leader has a significant positive effect on the polarization degree of network circle opinion. Regarding group polarization, the number of discussions in the group has a notable negative influence on its level of polarization. Additionally, both the authentication type and sentiment strength of opinion leaders significantly moderate this effect; however their influence has no significant moderating effect. Compared with individual users, group opinion leaders who are official users will enhance the influence relationship between the number of discussions in the circle group and the degree of group polarization, and the influence relationship between them will be weakened when the feelings of the group opinion leaders are enhanced. [Originality/Value] This study introduces the type of opinion leader as a moderating variable, explores the differences in the influence of various types of opinion leaders on the degree of group polarization of network circles, expands the relevant research on the influence mechanism of group polarization, and provides a new idea for the study of group polarization based on social network circles.

Keywords: Social network public opinion, Social network circles, Opinion polarization, Group polarization, Opinion leaders