The purpose of this study is to examine relationship between electroencephalographic (EEG) changes and the comfort which are induced by Mozart music. In this study, three sound stimulus that focused on the long time frequency spectrum were made: (1) normal Mozart music, (2) reversed Mozart music and (3) white noise made from the Mozart music. For five college students, EEG changes and the comfort were assessed. The EEG measurement was analyzed in alpha wave band (8.5-12.5Hz). The result of the assessment of the comfort indicated that Mozart music can be relaxed but white noise cannot be relaxed. However, the electric potential of the alpha wave band indicated upward trend by all stimulation. It was supposed that the rise in alpha wave reflected not only the comfort but the total emotion including unpleasantness. And it was thought that putting oneself in the imaginable environment greatly affected relaxing. This study suggests that the obedient harmony progress of the Mozart music was influences one's assessment of the comfort more than acoustic element of it.