The purpose of this study was to analyze the level of core competencies of undergraduate students at Seoul National University and to develop educational support programs to improve them. For this, K-CESA diagnosis was conducted for 52 undergraduates at Seoul National University. The students variables affecting core competencies of undergraduate students were analyzed including academic achievement(credit), admission type, major, and enrollment period. In addition, in- depth interviews were conducted with four students who had good academic achievement and competency level in order to extract factors affecting core competency improvement. As a result, the overall core competence level of Seoul National University students was relatively higher than that of the entire college students in Korea, especially in the comprehensive thinking capacity, but there was no significant difference in self-management or interpersonal relations. However, the higher the academic achievement, the higher the level of the six core competencies. The more the cumulative enrollment period, the higher the level of core competency. There were differences in the six areas depending on the major field, but it is necessary to analyze whether the influence is affected by the number of samples. The interviews of the students indicated that various learning experiences helped to improve the core competency level. We have identified a need for a variety of comparisons and programs to reduce student variability and improve core competencies. Based on their opinions, the components of the learning support program were derived and presented.