Purpose: Two purposes of this study were (a) to understand which variables of perfectionism can effectively predict the scores of learning problem and positive/negative affect; (b) to examine the mediating effectiveness of rumination on the relationships between perfectionism and learning problem, and between perfectionism and positive/negative affect. In this study, we conducted a survey of 941 undergraduate students (426 males and 515 females). Results: (a) Most of the perfectionism subscales can effectively predict the scores of learning problem and positive/negative affect. Especially, self-critical is the strongest predictor of the scores of learning problem and positive/negative affect. (b) Whereas functional rumination partially mediated the relationship between positive perfectionism and positive affect, reflective rumination partially mediated the relationship between negative perfectionism and negative affect/learning problem. Finally, brooding rumination partially mediated both the relationship between positive perfectionism and positive affect and the relationship between negative perfectionism and negative affect/learning problem. The implications of the findings, limitations and future research directions were discussed at the end of this paper.