A qualified career test could play an important role in providing information for students’ self-understanding and career decision-making. However, there are limitations and problems within the existing career aptitude tests in Taiwan. This study integrates psychological testing, adaptive techniques of psychometrics, and multimedia technology to establish a computerized adaptive career aptitude test (CACAT - J). The CACAT - J consists of brand new subject matters, dimensions and test items. Not only is the test more relevant with increased prediction power, but it also provides beneficial career counseling for students and teachers. The CACAT - J consisted of eight sub-tests: Verbal, Numerical, Spatial, Logical Reasoning, Scientific Reasoning, Observation, Aesthetics, and Creativity. There were 5820 participants in the present study. Reliability for the findings in this study ranged from .69 to .81. In terms of validity, the aptitude test scores were significantly correlated with junior high school students’ basic competence tests and ranged from .28 to .67. Through this test, students were able to understand their aptitudes on different skills that would enhance their career exploration and their capacity for effective career decision-making and planning.