This study explores the discourse space provided by the Internet technology especially for the social issue discussion, and the changed interpersonal relationship during those online discussions. Based on literature reviews, this study proposes a causal relation between network heterogeneity and cognitive dissonance, trying to explain the emerging “unfriend” phenomenon. Via analyzing the result of questionnaire designed for Weibo users (N = 287), the result reveals that interpersonal interaction motives, online civic participations are positive to network heterogeneity, and higher heterogeneity will result in higher degree of cognitive incongruity. To ease cognitive dissonance, people with a conservative inclined ideology are more likely to adjust their interpersonal relationship.