Objective For preventing the progression of diabetic complications, early detection of diabetic microcomplications is very important. In causing diabetic microangiopathy, hemorrheologic abnormalities are considered to be the potential mechanism.These changes of erythrocyte in turn make whole blood more viscous and may play an important role on the pathogenesis of vascular complications of diabetes. So in this study, we intended to discover the comprehensive hemorrheological parameters which can early detect diabetic microangiopathic complications. Methods 190 subjects were enrolled and their blood and urine samples were obtained. Also, they had a carotid IMT and their eye’s exam. Erythrocyte deformability (Elongation index), Aggregation index (AI), Critical shear stress were measured. All subjects were divided by five groups according to their past history and test results as follows: Healthy control (n = 28), prediabetes (pre-DM, n = 14), diabetes without vascular complications (DM-no Cx, n = 89), diabetes with microvascular complications (DM-microCx, n = 43) and diabetes with macrovascular complications (DM-macroCx, n = 15). The statistical analysis was performed using ANOVA with SPSS, ver. 20. Results A significant reduction of erythrocyte deformability was observed in DM-no Cx and DM-microCx group compared with healthy control (0.318 & 0.314 vs. 0.347 P < 0.05). Whereas, AI does not show significant tendency (P-value < 0.05). And critical shear stress shows significant difference between DM-no Cx and DM-microCx group (273.41 vs 339.47 P < 0.05). SS1/2/EImax that means the value of half shear stress devided by maximal Elongation Index shows significant reduction in DM-no Cx and DM-microCx group compared with healthy control (0.245 & 0.242 vs. 0.271 P < 0.05). Conclusion EI is a sensitive parameter to detect impairment of erythrocyte in diabetic process. And critical shear stress is also a useful parameter to detect diabetic microangiopathic complications early. Through analyzing tendency of these hemorrheologic factors, discovering the new hemorrheologic paramteter and making the equation or scoring system to detect diabetic microcomplications is very important task.