Although personality is regarded as an influence factor on the using and development of emotion regulation strategies, to date most studies with respect to the relationship between personality and emotion regulation strategies are cross–sectional surveys. Especially, limited study tests the effect of personality trait on two widely studied emotion regulation strategies (cognitive reappraisal and expressive suppression). Thus, the current study explores the effect of personality trait on cognitive reappraisal and expressive suppression through a longitudinal study, using a Chinese personality construct—interpersonal self–support. A series of previous studies support that interpersonal self–support is related to emotion. For example, interpersonal self–support is a protective factor against emotional symptoms. Further, some interpersonal self–support traits such as interpersonal independence, interpersonal initiative and interpersonal flexibility are assumed to influence cognitive reappraisal or/and expressive suppression. The Interpersonal Self–Support Scale for Adolescent Students (ISSS–AS) and Emotion Regulation Questionnaire (ERQ) were administrated to undergraduate students twice with 6 months interval. The participants were recruited from three universities in China. All participants were tested in groups in classroom settings. After informed consent, a battery of questionnaires was administrated to 410 students at time 1. Six month later (time 2), 374 of the 410 students completed these questionnaires again. The sample consisted of 87 males and 287 females, aged from 17 to 24. Correlation analysis showed that the scores of interpersonal initiative and interpersonal flexibility were significantly associated with cognitive reappraisal in the surveys. According to hypotheses, a path analysis via structural equation modeling with respect to interpersonal self–support traits predicting cognitive reappraisal and expressive suppression was constructed. The results showed that the paths from interpersonal initiative (p<.05) and interpersonal flexibility (p<.01) to cognitive reappraisal were significant. After deleting all non-significant paths, the final model was obtained. The results of the present study showed that interpersonal initiative and interpersonal flexibility predicted cognitive reappraisal 6 months later, even after controlling prior levels of cognitive reappraisal and the other interpersonal self–support traits. The results were consistent with prior cross–sectional surveys with regard to the relationship between extrovert and cognitive reappraisal. However, the predictive effects of interpersonal self–support traits on emotion suppression were not found. These results partly supported our hypotheses and suggested that certain personality trait may impact the using of a certain strategy of emotion regulation. Thus, the specific relationship between a trait and an emotion regulation strategy warrants explore in future. To our knowledge, this is the first try to explore the longitudinal relationship between personality and cognitive reappraisal and expressive suppression. Consequently, the present study may make a unique contribution on the causal relationship between personality traits and emotion regulation. In addition, as far as we know, no trait similar to interpersonal flexibility was found to be related to cognitive reappraisal. Interpersonal flexibility may be an important trait which influences cognitive reappraisal for Chinese people. Positive emotional dispositions may be one of the emotional mechanisms underlying the effects of interpersonal initiative and interpersonal flexibility on cognitive reappraisal. Our prior studies suggested that interpersonal initiative and interpersonal flexibility may refer to positive emotional disposition. The positive emotional disposition may lead people with high interpersonal initiative and high interpersonal flexibility to using positive emotion regulation strategies such as cognitive reappraisal to maintain positive feeling. Relational schema may be one of the cognitive mechanisms underlying the predictive relationship from interpersonal initiative and interpersonal flexibility to cognitive reappraisal. Relational schemas are regarded as cognitive units of interpersonal self-support. Relational schemas influence the interpersonal information processing, which may in turn impact the cognitive reappraisal of interpersonal events. In addition, high interpersonal flexibility individuals may be good at adjusting the appraisal on interpersonal events, thus they trend to use cognitive reappraisal strategy to adjust their feeling when they are confronted with emotional events.