The purpose of this study was to identify intrapsychic processes of self socialization in sex role development during late childhood and adolescence. For this purpose I investigated the sex-role stereotypes, sex-role ideology, sex-role identity, and self-esteem of 6th, 8th, and 10th graders and examined the causal relationships among these sex-role variables. Data were gathered through questionnaires administered twice with an interval of three months. The methods of analysis were one-way ANOVA, $x^2$, and multiple regression. The results showed, (1) Adolescents' sex-role stereotypes had significant relationships with sex typing. Subjects with low scores on sex-role stereotypes were more likely to show opposite sex typing. (2) Sex-role ideologies had significant relationships with sex typing. As Subjects agreed more with egalitarianism, they were more likely to exhibit opposite sex typing. (3) Adolescents' sex typing had significant relationships with their self-esteem. The androgynous group exhibited the highest scores on self-esteem. (4) Path analysis from the multiple regression analysis indicated different processes between sexes in sex-role development. In the boys' sex-role development, it was found that only masculinity contributed to self -esteem. Girls' masculinity also contributed most to self -esteem, but other sex -role variables such as femininity and sex-role stereotypes made some contributions to girls' self-esteem.