This study examined the psychological aspects of a single life with particular focus on the personality ＆ emotional characteristics, the social ＆ behavioral characteristics, marriage, happiness, and sex of singles. The sample consisted of 160 single male and female aged 30 to 49. The results of the questionnaire survey showed that the singles tended to be self-centered, especially when they did not have a plan to get married, and that most of the singles in the 30s wanted to have a friend of the other sex. In the view of marriage, young, male singles were more likely to form a family than old, female singles. Also, female singles, bereaved or divorced, were shown to have fear about marriage and negative attitudes toward marriage more than male, never-married singles did. Regarding the extent of happiness, old, female (rather than young, male) singles tended to be more satisfied with a single life. Besides, old, religious singles were less likely to feel lonely than young, unreligious singles. In addition, it appeared that college-graduated singles had rather liberal view on sex although singles generally showed rather conservative toward sex in this study. Therefore, the findings reveal that singles were self-centered, social, positive view on marriage, somewhat happy of a single life, and having a conservative attitude about sex. Further understanding of a single life in modem society is needed in future studies.