Abstract: Objective：To investigate the incidence of metabolic syndrome in patients with primary hypertension and non-functional adrenal incidentaloma (NFAI) and to analyze the correlation between the metabolic syndrome and the cortisol levels. Methods：Fifty-six primary hypertension patients combined with NFAI (NFAI group) and 58 primary hypertension patients with normal adrenal morphology (EH group) admitted in the Department of Endocrinology, Zhongshan Hospital between October 2014 and April 2015 were selected. Physical examination parameters such as height, weight, abdominal circumference, and blood pressure were collected. Electrolytes, lipid profiles, fasting and 2-h postprandial blood glucose (2-h PG) levels, and the cortisol levels after the overnight 1-mg dexamethasone test (ONDST) were analyzed. The patients in NFAI and EH groups were further divided into metabolic syndrome group (MS group) and non-metabolic syndrome group (NMS group)，the cortisol levels after ONDST were compared among different groups. Results：Diastolic blood pressure, body mass index (BMI), abdominal circumference, 2-h PG, triglyceride, and ONDST cortisol levels were significantly higher in the NFAI group than those in the EH group (P<0.05). There were 22 patients (39.2%) with metabolic syndrome in the 56 NFAI patients, and the proportion was higher than that of the EH group (14 patients, 24.1%, P<0.05). In the NFAI group, the cortisol level after ONDST in the MS subgroup was significantly higher than that in the NMS subgroup. The abnormal number of metabolic syndrome in the NFAI group gradually increased along with the cortisol level after ONDST. Conclusions：The prevalence of metabolic syndrome in primary hypertension patients combined with NFAI is relatively high, which is correlated with the cortisol level after ONDST.