Aim To investigate the relationship between serum 25-hydroxyvitamin D (25-(OH)D) and parathyroid hormone (PTH) levels and hypertension in patients with type 2 diabetes. Methods A retrospective analysis of 128 patients with type 2 diabetes was divided into hypertension group (89 cases) and non-hypertension group (39 cases) according to whether they had priary hypertension. General information of the subjects and serum PTH, 25-(OH) VitD were collected. To analyze the relationship between 25-(OH)VitD, PTH and hypertension in diabetic patients. Results Serum 25-(OH)D levels were lower in the patients with hypertension than in the non-combined hypertension group (P<0.001). Difference in PTH of the two groups lacked statistical significance(P=0.132). Pearson correlation analysis showed that 25-(OH)D was negatively correlated with PTH (r=－0.182, P<0.05). Binary Logistic regression analysis showed that 25-(OH)D reduction was a risk factor for type 2 diabetes with hypertension (OR=0.5,5%CI 0.883-0.991, P=0.023), whereas elevated PTH is not a risk factor for hypertension in diabetic patients. Conclusion Diabetic patients are prone to decrease with 25-(OH)D, and 25-(OH)D reduction is a risk factor for hypertension in diabetic patients.