Objective To investigate the relative relationship between the degrees of seriousness of obstructive sleep apnea hypopnea syndrome and the variation of blood pressure in exercise Methods 49 patients with obstructive sleep apnea hypopnea syndrome without using anti hypertension drugs, were used as our objectives We performed the exercise test with bicycle like instrument During the test, we measured the blood pressure, plasma lactic acid and arterial blood gases Then we analysed the blood pressure in exercise, BMI, clinical symptoms and the mean of the lowest SpO2 measured by over night polysomnography Results The variation of blood pressure in exercise was related to the clinical symptoms and the mean of the lowest SpO2, but not to the BMI Conclusion The degrees of seriousness of obstructive sleep apnea hypopnea syndrome may be related to the elevation of blood pressure