The purpose of this study was to investigate the effects of musical stimuli for relaxation of the human body nervous system. The participants were 30 college students with above average scores on stress measurements. Each participant took performed two treatments. The first treatment involved listening to relaxation music for 20 min. The second treatment involved listening to self selected (preferred) music for 20 min. The EEG and ECG of each participant was recorded before and after listening to the music. The data were analyzed by SPSS program using a paired t-test. Both types of music showed an increase in the relaxation index and a decrease in heart rate. The balance of autonomic nervous system has effective changes. Also, the relaxation music was more effective in changes in the relaxation index, heart rate and ANS balance than self-selected music. We identified that both music types have effects for relaxation by evidence of the neurophysiological aspects.