Abstract: To investigate the characteristics of ambulatory blood pressure in the patients with obstructive sleep　apneahypopnea syndrome(OSAHS). Methods： With the use of polysomnography， 112 snorers were examined and divided into OSAHS and non OSAHS groups. Meanwhile， with the use of continuous Holter ECG and blood pressure (Bp) measurement， the daytonight rhythm of Bp was compared between two groups. Result： There were significantly higher incidence of hypertension and disappearance of daytonight rhythm of Bp in OSAHS group than in nonOSAHS group. Conclusion： OSAHS can induce hypertension and disappearance of daytonight rhythm of Bp.

Key words: Snore, Obstructive sleep apnea syndrome, Ambulatory blood pressure