This study investigated differences in cosmetic buying behavior and personal characteristics between cosmetic involvement groups. Cosmetics buying behavior refers to reason for using cosmetics, use of information sources, selection criteria, place of purchase, use/non-use of cosmetics, purchase propensity, purchase frequency, purchase amount, and satisfaction with cosmetics. Personal characteristic contains pursuing image, age, residence area, job, and average household monthly income. Data was collected from 5-10 December 2016, from 308 females in their 20s using an internet survey. The analysis included descriptive statistics, t-tests, Mann-Whitney U tests, and chi-square tests. The respondents were divided into two groups (a high cosmetic involvement group and a low cosmetic involvement group) according to the degree of cosmetic involvement. The results of t-tests revealed significant differences between groups in terms of reasons for using cosmetics, use of information sources, selection criteria, purchase frequency, place of purchase, use/non-use of cosmetics, and satisfaction with cosmetics. The results of Mann-Whitney U tests highlighted a significant difference in purchase frequency between both groups. The results of chi-square tests indicated significant differences in purchase frequency, purchase amount, pursuing image, and average household monthly income. However, no significant differences were evident in terms of purchase propensity, age, job, and area of residence between groups.