The purpose of this study is to analyze the impact of organizing and operating a competency-based major curriculum of teacher training colleges on teaching aptitude and personality, focusing on the case of K University. Through this, implications for improving competency-based major curriculum for teacher training courses were derived. The research method was to confirm the changes in teaching aptitude and personality of prospective teachers in teacher training departments that organized and operated a competency-based major curriculum using a paired table t-test. In addition, an independent sample t-test was conducted to compare teaching aptitude and personality between general university education departments and general university teacher training courses. Finally, the results of descriptive statistics were utilized to compare and analyze the sub-elements of teaching aptitude and personality. As a result of this study, the effects of the organization and operation of competency-based major education curriculum of teacher training colleges on teaching aptitude and personality are as follows: First, there was a statistically significant difference between the pre- and post-scores of teaching aptitude and personality of teacher training departments, confirming that the organization and operation of competency-based major education curriculum of teacher training departments had a positive effect on teaching aptitude and personality. Second, as a result of comparing and analyzing the changes in teaching aptitude and personality between general university education departments and general university teacher training courses, the average score of teaching aptitude and personality of general university teacher training courses was higher than that of general university education departments, and the difference was also significant. Third, as a result of comparing and analyzing the sub-elements of teaching aptitude and recognition, it was confirmed that the change in cognitive elements had the greatest effect and the change in emotional elements had the lowest effect. Therefore, teacher training curricula should be organized and operated based on major competencies including teacher competency, but it is essential to design and develop competency-based major education curriculum based on systematic derivation of teacher competency that appropriately reflects teacher training elements. In addition, in the process of designing and developing a competency-based major education curriculum, it is necessary to identify the strengths and weaknesses of each sub-element based on a diagnostic analysis of prospective teachers' teaching aptitude and personality, and to continuously take measures such as developing and reorganizing subjects to supplement weaknesses, restructuring subject content, and improving teaching methods.