This study constructed a situation-based career interest assessment (SCIA) that is suitable for applying to junior high school students. The assessment framework is based on Holland’s theory of vocational interest. The subjects for the pilot study and the formal test were 1,072 junior high school students and 1,136 junior high school students, respectively. The results of reliability tests produced correlation coefficients between .77 and .95, exploratory factor analysis produced factor loadings between .32 and .92 for six factors, and confirmatory factor analysis produced relative fit indices of .95 across the comparative fit index and nonnormed fit index, indicating a satisfactory goodness of fit. Convergent and discriminant validity analyses indicated that the SCIA has acceptable construct validity. Multidimensional scaling analysis, internal correlation, and randomization test showed that the interest structure of adolescents and the relationship among interest types are only partially consistent with Holland’s theory.