This study was to develop competency diagnostic instrument based on subjective perception for undergraduate students. 500 college students participated in the survey and procedures was included such as literature research, expert council, preliminary survey, and statistical analysis of result to develop competency diagnostic instrument. Exploratory and confirmatory factor analysis were conducted based on the survey data collected to examine the reliability and validity of competency diagnostic instrument. As a result of exploratory factor analysis, three factors for each competency were composed, and a total of 70 questions were completed. As a result of confirmatory factor analysis, it was confirmed that the model fit was suitable. Construct validity were verified for the measurement model by comprehensively considering the factor load standardization coefficient, CR, AVE for each competency. The self-awareness-based competency diagnostic instrument consisted of the final 70 questions and was confirmed to be a scale with reliability and validity.