Objective To investigate the correlation between serum endotherin-1 (ET-1), homocysteine (Hcy), hypersensitive C-reactive protein (HS-CRP) and interleukin 6 (IL-6) and the degree of AS in patients with T2DM with masked hypertenion. Methods 29 patients with T2DM treated in our hospital from February 2019 to may 2020 were selected. Their blood pressure was less than 140/90 mmHg. They were divided into NH group (n=76) and MHT group (n=53) according to 24-h ambulatory blood pressure monitoring. The contents of serum ET-1, Hcy, hs-CRP and IL-6 were measured by enzyme-linked immunosorbent assay, and the brachial ankle artery baPWV, vasodilation function (FMD) and arterial intima-media thickness (IMT) were measured. The correlation between serum ET-1, Hcy, hs-CRP and IL-6 and baPWV, FMD and IMT was analyzed.Results Compared with NH group, the levels of ET-1, Hcy, hs-CRP, IL-6, baPWV and IMT in MHT group increased significantly (P＜0.05), and FMD decreased significantly (P＜0.05). The levels of serum ET-1, Hcy, hs-CRP and IL-6 were positively correlated with baPWV and IMT, and negatively correlated with FMD (P＜0.05). High levels of ET-1, Hcy, hs-CRP, IL-6 and TC were important risk factors for the degree of arteriosclerosis in T2DM patients with MHT (P＜0.05).Conclusion The degree of atherosclerosis with T2DM combined with MHT is associated with inflammatory factors and impaired endothelial function.