Abstract: Objective To understand the levels of plasma homocysteine in hypertensives with obstructive sleep apnea syndrome. Methods Select randomly hypertensives 227 cases from March 2007 to March 2008 in the people's Hospital of Xin Jiang Autonomous Region, Investigate of sleep monitoring, the levels of plasma homocysteine and blood lipids, blood glucose, carotid artery plaque detection, and smoking, drinking related risk factors,The subjects were divided into simple hypertension, high blood pressure combined with mild OSAS and hypertension with moderate to severe OSAS group. Results The levels of plasma homocysteine in hypertensivs with moderate and severe OSAS were higher than simple hypertension group, P < 0. 05. The levels of plasma homocysteine increased with the degree of OSAS in hypertensives. Conclusion OSAS may be the risk factor of in creased The levels of plasma homocysteine in hypertensives with sleep apnea syndrome.