Researchers and practitioners alike have noted that emotion suppression has been associated with poor psychological and physical health, and negative social consequences. Nevertheless, Chinese culture encourages emotional suppression in circumstances where there is in an effort to preserve relationships. Harmonious social relationships are of utmost importance in Chinese culture, forbearance has been considered as a common and valued emotional regulation strategy in interpersonal conflicts. This study attempted to understand why people suppress their emotion expression. The scope focused on college students’ interpersonal context. A qualitative approach using semi-structured interview and emotion journal was applied to get data. In addition to analyzing 22 emotional journals, there were 24 undergraduates participated to interview. Results showed there were many reasons for suppressing the negative emotions, including maintaining harmonious relations, avoiding the negative consequence of expression, controlling impulse rationally, adhering to ethical etiquette, emotion expression is useless, and poor in emotional expression. The suppression of positive emotion expression were due to avoiding show off too much, worrying about others’ jealousy, considering the feelings of others, and being not used to express. In addition, whether people express emotions or suppress them, depends on the communal relationship and immediate situation. The stronger the relationship, the more possible to express the emotions. In many contexts, expressive suppression appears to be a risk form of emotion regulation, but in some of contexts, the outcome may well be worthwhile to take the risk. In light of these analysis, this study suggest that, in Chinese culture, the critical question becomes not whether it is generally better to express or suppress emotion, but when, where, and with whom it is advantageous to suppress rather than express one’s emotions.