The present study was conducted to evaluate the model which investigate predictive role of emotional dysregulation (ED), intolerance of uncertainty (IU), experiential avoidance (EA) and repetitive negative thinking (RNT) in positive and negative perfectionism. Participants were 412 B.S students of Tehran university, Allameh Tabatabei and Kharazmi university.The positive and negative perfectionism, repetitive negative thinking questionnaire, disorder in emotion regulation scale, intolerance of uncertainty scale and multidimensional experiential avoidance questionnaire were used for gathering data. Data was analyzed by structural equations modeling. ED does not have significant relationship with positive perfectionism. But there is mediated and unmediated significant relationship between ED and negative perfectionism. IU has unmediated significant relationship with perfectionism and has mediated and unmediated significant relationship with negative perfectionism. EA has unmediated significant relationship with perfectionism and has mediated and unmediated significant relationship with negative perfectionism. ED, IU and EA were significantly predicted 12 percent of positive perfectionisms, 64 percent of negative perfectionisms and 58 percent of RNT. The results showed that positive and negative perfectionism are two different structural models. And RNT mediates the association just between negative perfectionism and some of outcome variables.