Music is known to have both stimulatory and sedative effects. We investigated whether music modulated the arousal level. EEGs, EOG, SPR, plethysmograph, and skin temperature were recorded on 14 students (mean=22.1 yrs) during sessions of (1) baseline (pre-rest), (2) preparations of arousal (task or rest), (3) music (stimulative or calm), (4) after-effects (post-rest). Seven subjects, who were assigned to the high arousal group were preparatively increased their arousal level by the cognitive task before the music session. Other seven subjects, who were assigned to low arousal group were instructed to relax in the rest period before music session. In the high arousal group, the EEG amplitude in alpha 3 and beta bands were significantly higher in the task session than in the baseline session. In the music session the amplitude in alpha 3 and beta bands were decreased in both the stimulative and the calm music conditions. The results show that the music may induce the de-arousing effects on the subjects in the high arousal states. This tendency was clear in the calm music rather than in the stimulative music. In the low arousal group, on the contrary, the amplitude in alpha 2 band was significantly lower in the rest session than in the baseline session. In the music session the amplitude in alpha 1 band increased in both the stimulative and the calm music conditions, suggesting that the music may induce the arousing effects on the subjects in lower aroused states. This tendency was more remarkable in the stimulative music rather than in the calm music. These results support a hypothesis that the music effects on the arousal mechanisms and the different type of music induces a different effect on the arousal level.