Purpose: This study aimed to identify differences in contraception behavior and related factors between unmarried female and male. Methods: A cross-sectional survey design with a convenient sampling was used. From Seoul, 107 women and 96 men were recruited. A structured questionnaire was self-administered from July 14, 2008 to September 2, 2008. Results: The average ages of women and men were 26.9 and 27.8 years old, respectively. Fiftysix percent of women and 85.4% of men have experienced sexual intercourse. There were no differences between female and male in attitude toward contraception, subjective norm, and contraception behavior, while female had higher score of self-efficacy for contraception (p=.02) and intention of contraception (p=.02). There was positive correlation with subjective norm (r=.22, p<.05), self-efficacy (r=.53, p<.01) in male and attitude (r=.32, p<.05), selfefficacy (r=49, p<.01) in female. According to the result of multiple regression, the significant factor of contraception behavior was self-efficacy for both female (${eta}$=.49, p=.00) and male (${eta}$=.53, p=.00). Conclusion: To improve contraception behavior for unmarried female and male, it is necessary to develop proper sex education program to enhance self-efficacy for contraception. Adjusted education program by this result will contribute to increase sexual health for female and male.