The purpose of this research is to investigate whether music activity therapy can reduce elementary students' stress level caused by privately tutored after-school teachings. The subjects of this research were twenty four students in Ok-cheon county, ranging from 4th to 6th grade. They were selected among those who had high by Extra-Curricular classes scores on the stress inventory. The experimental group was given 12 sessions (twice a week and for fifty minutes) of music treatment and the control group was given no treatment. The result after the music activity treatment showed a significant difference in the stress scores between the two groups(p<.05). The second result comparing the subordinate areas showed a significant difference in the areas of studies, family, school(p<.05), mind, and the future(p<.01). These results show the effectiveness of music therapy in general which implies that music is an effective method to reduce the stress of a elementary school students.