Aim To detect the expression and distribution of macrophage inflammatory protein-1α (MIP-1α)in atherosclerotic tunica intima of artery from type 2 diabetics and non-diabetics in order to try to find out the effect of MIP-1α on the formation and development of atherosclerosis in type 2 diabetics. Methods We used the immunohistochemistry method to detect the expression and distribution of MIP-1α in atherosclerotic tunica intima of artery from 13 type 2 diabetics, 15 non-diabetics and normal tunica intima of artery from 7 healthy people, respectively. Then computer image analyzer was used in relative quantu analysis. Results MIP-1α was absent in normal arteries with average gray value of 234.27±8.04. There was different expression of MIP-1α in different-stage tunica intima of artery from non-diabetics with atherosclerosis: With the progression of atherosclerosis, the immunoreactivity of MIP-1α increased with average gray value of 168.40±7.69 in fatty steaks and 173.67±6.56 in fibrous plaques. MIP-1α was mainly in endothelial cells and foam cells during fatty steaks, while MIP-1α was mainly in foam cells and there was little expression in endothelial cells during fibrous plaques. Average gray value of MIP-1αin fatty steaks from type 2 diabetics was 132.73±6.01. There was a significant difference between average gray value in fatty steaks from non-diabetics and average gray value in fatty steaks from type 2 diabetics (p<0.05). Average gray value of MIP-1α in fibrous plaques from type 2 diabetics was 138.68±9.41. There was a significant difference between average gray value in fibrous plaques from non-diabetics and average gray value in fibrous plaques from type 2 diabetics (p<0.05). There were strong expression of MIP-1αin endothelial cells and foam cells during two stages of type 2 diabetics. Conclusions MIP-1α was absent in normal arter-