The purpose of the study is to investigate effects of self-concept on daily stress for College students. This study also analyzed the mean differences and the correlations of these variables by gender. Study participants were 198 college students from two 4-year universities located in Seoul. There were 138(69.7%) male college students and 60(30.3%) female college students. The stress and self-concept scale were used including 5 domains: stress(school life, interpersonal relationship, self problem, environment problem, family life), self-concept(general, academic, family and social, emotional, physical self-concept). There were gender differences in general and physical self-concept, self problem stress. That is, female students have lower general, physical self-concept and larger self problem stress than male students. The relationships between self-concept and stress were negative in male and female groups: the higher the self-concept, lower the stress. The effect of self-concept on stress were different results depending on gender. The explained variance in stress was higher in female group. And, the significant self-concept domains were different depending on gender. Especially, the results show that physical self-concept was the important domain only for the female group.