The purpose of this study was to verify relations among career interest-major agreement, career interest-aspiration agreement, career maturity, and academic achievement of vocational high school students. Through this study, back up plan to support students' successful academic performance would be suggested based on career education and counseling. To reach the goal, survey questionnaires were handed out to 330 vocational high school students who were sampled randomly from 6 schools located in Seoul, Gangwon, and Gyeongnam province. The data analyzed by ANOVA, Scheffe', and Multi-Regression methods. According to the results, career interest-major agreement and career maturity level affected to school achievements. Career maturity level came out as the most explainable variable about school achievement. Based on these results, the necessity of systematic and continuable career education and counseling was discussed. Especially, the necessity of sufficient consideration of individual career interest was stressed in that interest-major agreement would meaningfully affects student's school achievement. Finally, the significance and limitation of this study and suggestions for the follow up studies were discussed.