The purpose of this study was to examine the relationship between career decision-making self-efficacy confidence and career maturity. Twice with an 8 month interval, the scale of career decision-making self-efficacy expectations and the educational/occupational career maturity scale were administered to 71 2nd-grade high school students. It was found that students who showed high scores in the occupational career maturity scale and low scores in the self-efficacy scale did not keep their occupational maturity score during the interval. In contrast, all students scored highly on the educational career maturity scale at the second time. These findings suggested that career decision-making self-efficacy had significant influence on the occupational career maturity, while significantly irrelevant to the educational career maturity.