Objectives: It is important to control stress and lifestyle to prevent stress disorder and lifestyle-related diseases that have become serious problems all over the world recently. Transactional Analysis theory is one of the most valuable theories to prevent their problems. In this study, the effects of Ego States, Permeability Control Power, and Basic Positions in Transactional Analysis Theory on psychological symptoms in university students were examined in order to understand total control over one's ego states. Method: One hundred sixty nine university students (143 males, 26 females; mean age, 18.35 ± 1.01 years) participated in this study. They responded to PC Egogram, a measure of one's Ego States and Permeability Control Power, and OKgram, a measure of one's Basic Positions. Their psychological symptoms were assessed by Hopkins Symptom Checklist (HSCL). Results: In order to evaluate the influences of the Ego States, Permeability Control Power and Basic Positions on psychological symptoms, multiple regression analysis was performed. The result showed that Critical Parent (CP) and Free Child (FC) ego states had positive influences on psychological symptoms. On the other hand, Permeability Control Power (PC) scale had a negative influence on anxiety, obsessive-compulsive and interpersonal sensitivity. Additionally, the I'm OK and the You're OK position negatively influenced anxiety, depression and interpersonal sensitivity. Moreover, a one-way analysis of variance was performed to compare the types of ego states on psychological symptoms. A significant difference was observed between the FC highest type and the Adapted Child (AC) highest type in Egogram profile. In other words, these results suggest that individuals with free-spirited type are more likely to show psychosomatic symptoms compared to those with socializing type. However, the relationship between FC ego state and psychological symptoms might differ depending on the Adult (A) score. To test this idea, correlation analyses were performed. The results showed that positive correlation was observed among those who had lower A score. No such relationship was found in those with higher A score. Conclusions: It was shown that stern character of CP and impulsive side of FC were related to the increased psychological symptoms. However, the results also showed the possibility that FC ego state accompanied with high A ego state would not be related to psychological symptoms. On the other hand, the I'm OK Position, the You're OK Position and PC were related to the reduction of psychological symptoms and would regulate stress.