The present study investigated relationships between reasons for having sexual intercourse with an intimate partner; satisfaction with sexual intercourse and satisfaction with their relationship among university students. The participants were 141 university students who have intimate partners and have sexual intercourse with their partner. They were asked to respond to 45 questions relating to reasons for having sexual intercourse with their partner. In addition, there were a question relating to satisfaction with sexual intercourse; and further a question relating to satisfaction with their relationship. A results of factor analysis identified six factors; sexual desire, confirmation of their love, demand of their partner, pressure from society to have sexual intercourse, a method of control, and seizing an opportunity. Structural equation modeling showed that confirmation of their love increased their satisfaction with sexual intercourse, which in turn raised their satisfaction with their relationship. In contrast, in the case of males, pressure to have sexual intercourse lowered their satisfaction with sexual intercourse, and consequently their satisfaction with their relationship went down.