Abstract: Objective：To investigate the changes and the relationship of serum homocysteine and platelet granule membrane protein 140 in patients with diabetic Nephropathy (DN). Methods：50 cases of the control group of healthy patients；150 cases with type 2 diabetes mellitus is divided into three groups of patients with normal albuminuria group, microalbuminuria and clinical proteinuria group, each group contens 50 cases. Their serum levels of homocysteine, the plasma Platelet granule membrane protein 140 were measured. Results：In all patients with diabetes the serum homocysteine and the plasma Platelet granule membrane protein 140 levels were significantly higher than the normal control group (P <0.01); micro-albuminuria group and clinical proteinuria group were higher than normal albuminuria group and normal control group (P <0.01); clinical proteinuria group was higher than the micro-albuminuria group (P <0.01); The Serum homocysteine level was positively correlated with the plasma Platelet granule membrane protein 140 levels.Conclusion：The serum homocysteine level and the plasma Platelet granule membrane protein 140 level is higher in DN patients,they have correlation.