Our study aims to detect the changes of adiponectin (APN), endothelin 1 (ET)-1, nitric oxide (NO), cystatin C (cysC) in diabetic limb arterial occlusion (DLAO) patients and unravel their associations with endothelial function. Total 240 type 2 diabetes mellitus (T2DM) patients were divided into a DM group (n = 80, ankle brachial index (ABI) ≥ 0.9) and a DLAO group (n = 160, ABI < 0.9). ABI, flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD), serum APN, ET-1, NO, and cysC were compared. There were significant increases in cysC and ET-1, and significant decreases in APN, NO, FMD and NMD of DLAO patients compared to T2DM patients. Serum APN and NO were positively correlated with ABI, while serum cysC and ET-1 were negatively correlated with ABI. cysC, ET-1 and diastolic blood pressure (DBP) were independent predictors of the severity of DLAO. Serum APN was positively correlated with FMD, NMD and NO, but was negatively correlated with ET-1 and cysC. FMD and NMD were positively correlated with APN and NO, and negatively correlated with ET-1 and cysC. Our study deciphers opposite roles of APN, NO, cysC and ET-1 in the development of DLAO and maintaining endothelial function.