The purpose of this study was to develop a scale for socialization and investigatethe influences of socialization, responsibility for sex, sex role attitude, love style(ludus)and trust/relief in sexual decision-making (contraceptive use). 399 undergraduates, 237 female and 162 male, participated in the research. It was found that six factors could be extracted using factor analysis ofsocialization: assertiveness, intelligent choice, respect for others, future plans, will power and basic socialization. In women, determinants of contraceptive use wereresponsibility for sex and sex-role attitude. In males these were responsibility forsex and basic socialization. The results suggest the importance of education toimprove socialization, including in career education.