The purpose of this study was to investigate the structure of negative feelings caused by negative events in opposite-sex relationships, and the relation between negative feelings and sex difference, relationship with partner, coping behaviors and relationship satisfaction. Three hundred and fifty-six undergraduates responded to a questionnaire asking about their relationships with their partners, negative events, negative feelings, their coping behaviors, relationship satisfaction and a love scale. Negative feelings were classified into affiliation-dissatisfaction and aggressive/refusal feelings. Affiliation-dissatisfaction was composed of sadness, anxiety and so on. It was caused by distance from partners, and did not influence the relationship satisfaction of lovers. The aggressive/refusal feelings were composed of irritation, anger and so on. They were caused by interference from partners. The more frequently they occurred, the lower relationship satisfaction was.