The purpose of this study was to compare the application method of ultrasound on the alteration of pressure pain threshold of myofascial trigger points. We used thirty patients with mayofascial pain syndrome in upper trapezius. Participants classified according to each group in non noxious dose, noxious dose by the ultrasound. The test was measured continuously pre test, post-test by algometer. The following results were obtained; 1. Pressure pain threshold were significantly increased in non-noxious dose and noxious dose group(p<.001). 2. In noxious dose group, pressure pain threshold were more significantly increased than non-noxious dose group(p<.001). These results lead us to the conclusion that non-noxious dose and noxious dose were significantly increased pressure pain threshold of upper trapezius trigger points. Therefore, a further direction of this study will be to provide more evidence that noxious dose have more effect on pressure pain threshold of myofascial trigger points.