This study was conducted to clarify the influence of circuit training carried out once a week on the mood state and physical fitness of college students. Thirty-five healthy college students (6 males, 29 females) participated. Students completed an exercise set consisting of six items, and repeated these in sets of three during physical education class once per week for 8 weeks. The effect of the training was evaluated by comparison of the maximal repetition (MR) values in the maximum score test (MST) carried out one week before and one week after a training period. Mood state was determined by Mood Check List-Short Form 1 (MCL-S.1), by which mood state is assessed as a pleasant feeling, a relaxed feeling, and a feeling of anxiety. The students made these assessments immediately before and 5 minutes after every exercise. The influence of the physical fitness level was assessed in female students with high TS values (HG, n=6) and in female students with low TS values (LG, n=6). All of the MR values in the MSTs and the height of a vertical jump were increased significantly after the training period. The results of repeated measures ANOVA performed on data obtained from all of the students showed that the pleasant feeling score increased significantly after the exercise (p<0.05), whereas the relaxed feeling and the feeling of anxiety scores did not change. The mood state scores before and after exercise did not show a significant difference between the HG and the LG. The pleasant feeling scores for both groups were positive in both the HG and LG, indicating that the exercise resulted in a desirable mood state. These results showed that the circuit training program was effective for increasing the level of physical fitness and that it improved the pleasant feeling of individuals, regardless of their physical fitness level.