Objectives:The objective of this study is to find out the differences in psychopathology, temperament, and character factorsbetween young adults with and without childhood attention-deficit hyperactivity disorder (ADHD) symptoms. Methods:The subjects consisted of 314 university students (male=72, female=242) in Gongju. They were divided into childhoodADHD group (N=54) and normal group (N=260) to the Wender-Utah Rating Scale. Participants were assessed using KoreanAdult ADHD Scale, Beck Depression Inventory-II, Beck Anxiety Inventory, Kimberly Young’s Internet Addiction Test, BarrattImpulsiveness Scale, Paranoia Scale, Korean-Schizotypal Ambivalence Scale, Lubben Social Network Scale, andTemperament and Character Inventory-Revised. Descriptive statistics, t-test, chi-square, spearman correlation, and stepwise multipleregression were applied to analyze the data. Results:Participants with childhood ADHD symptoms had high level of adult ADHD symptoms (p<.001), impulsiveness(p=.001), depression (p<.001), anxiety (p<.001), internet addiction (p<.001), paranoia tendency (p<.001) and low level of selfesteem(p<.001) compared to normal group. Self-directedness (p<.001) was lower, Harm avoidance (p=.001) and Self-transcendence(p=.029) were higher in the childhood ADHD group. In correlation and stepwise multiple regression, childhood ADHDsymptoms were significantly associated with cooperativeness (r=-0.515 and β=-0.547, p<.001 respectively). Conclusion:This result showed that young adults with childhood ADHD symptoms had various forms of psychopathologyand childhood ADHD symptoms were influenced by character such as cooperativeness. Therefore, more thorough evaluation regardingchildhood ADHD symptoms is needed.