【Objective】To explore the relationship between the miR- 132 expression in serum and cognitive deficits of OSA. 【Methods】 66 Chinese adults age 30 to 60 years old were enrolled and categorized into two groups based on Montreal Cognitive Assessment（MoCA）scores： OSA patients with cognitive impairment（OSAI，n=36），OSA patients without cognitive impairment（OSAN，n=30），and thirty adults without OSA as healthy control group（HC，n=30）. Out- of- center cardiopulmonary sleep testing （OCST） and MoCA assessment were performed and the relative expression of miR-132 in serum was detected by PCR.【Results】No significant difference was observed in age，education，gender and hypertension（P>0.05）. The relative expression level of miR-132 was significantly up-regulated in OSAI patient′s serum compared to the OSAN and HC patients （P<0.001），and had a positive correlation with MoCA score （r=- 0.726，P<0.001）. ROC analyses showed that the areas under the curve（AUC）were statistically significant from the line of identity in OSA with cognitive impairment（AUC=0.935，95% CI：0.890- 0.981，P<0.001）and in OSA（AUC=0.787，95% CI：0.695-0.879，P<0.001）.【Conclusions】Elevated serum miR-132 expression levels are closely related to the diagnosis of OSA and its cognitive dysfunction. Detection of serum miR- 132 may be a potential indicator of cognitive dysfunction and diagnosis in OSA patients.