Objective:To evaluate the changes of serum matrix metalloproteinase-9 (mmp-9) in patients of incipient diabetic nephropathy with or without macrovascular disease and to analyze the factors associated with homocysteine(hcy),interleukin-6(IL-6),tumor necrosis factor-alpha (TNF-α),highly sensitive C-reactive protein (hsCRP),HbA1c and lipid profile in those patients in order to know whether this marker or other factors are more important to induce diabetic macrovascular disease.Methods:Type 2 diabetes mellitus(T2DM) subjects with incipient diabetic nephropathy with or without macrovascular disease were selected for participation and divided into 2 groups.The patients in group 1(n=38) used insulin,and patients in group 2 (n=34) were treated with an oral antidiabetic drug.Then serum mmp-9,hcy,IL-6 and TNF-α in these patients were measured, and compared to the healthy subjects as control (n=16).The resuits were analyzed by SPSS13.Results:Serum romp-9 and hcy of the patients having incipient diabetic nephropathy with macrovaseular disease were higher than that of patients without macrovascular disease (P＜0.01).For insulin-injected patients,whether they accompanied with macrovascular diseases or not,the serum levels of mmp-9,hcy,IL-6 and TNF-α were all lower,but no significant statistics compared with non-insulin used patients or the healthy subjects.The serum level of mmp-9 was more correlatedwith the serum hcv in antidiabetic drug used patients.(P＜0.000) Conclusion:The serum level of mmp-9 plays an important role of pathogenesis in the macrovascular disease in the incipient diabetic patients,and the serum level of hcy also can reflect the severely degree of macrovascular disease in these patients,insulin can reduce these markers.