Objective To know the prevalence of chronic obstructive pulmonary disease(COPD) in patients with obstructive sleep apnea-hypopnea syndrome(OSAHS) in Kunming Yunnan Province, and the clinical symptom of OS.Methods Retrospective study of 4 636 cases of patients with snoring, excluding COPD in addition to chronic respiratory disease and assess the patient`s condition.The test included AHI, BMI, Epworth sleepiness scale, lung function.The index of OS was confirmed by AHI>5 times/h and FEV1/FVC<70%.Results During the period of 2006 to 2012, he prevalence of COPD in patients with OSAHS was 10.1% [95% confidence interval (CI) 9.1%-11.1%] in Kunming Yunnan Province.And male`s OS prevalence rate is higher than the female(male 10.2%;female 9.7%).The OS patients` average age was 56.9±14.1, the mean AHI was (47.46±26.79) times/h, and the average FEV1/FVC was 60.09%±23.57%.Polysomnographyresults show that patients suffered obvious hypoxiaat night in both OSAHS group and OS group, but it was more significant in OS group.Pulmonary function test showed that OS patients have more serious chronic obstructive pulmonary disease.Conclusions The prevalence of COPD in OSAHS patients was high in Kunming, Yunnan Province, and the prevalence rate in old group reached more than 24%.In addition, the sympotms of patients with OS were more severe than those with only OSAHS or COPD in lung function and hyoxemia.