Objeetive To explore the relationship among the glomerular mesangium components,degree of renal lesion and glomerulosclerosis in patients with type 2 DM.Method A quantitative study of type Ⅳ collagen in kidneys taken from twenty-one patients with type 2 DM and ten-two control autoptical renal tissue specimens were investigated by immunochemical techniques,computer image analysis system.Results The amounts of type Ⅳ collagen were increased parallel with advances of glomerulosclerosis and renal arteriolosclerosis in patients with type 2 DM,but the collagen had not obviously elevation in renal failure patients.Conclusions The increased type Ⅳ collagen is a characteristic manifestation of early and moderate lesions of glomerulosclerosis in type 2 DM.Quantitative determination of glomerular mesangium components could be a good index to judge the lesion degree of kidney.