OSAS patients are required to fill in questionnaire.And Inflammation biomarkers and Oxidative Stress biomarkers and ultrasonic will be tested.Then patients are randomly allocated to one of two groups. One group is treated with oral intake of Antioxidant Carbocysteine 500mg tid. The second group is treated with CPAP. After 6 weeks treatment, all patients will take the overnight polysomnogram test again, and take questionnaire, blood , ultrasonic test.