Objective To investigate the Clinical Value of Combined Determination of Serum cystatin C and Retinol-binding protein in diabetic nephropathy.Methods Immunoturbidimetry was employed to analyze Cystatin C(Cys C)and Retinol-binding protein;(RBP) from 94 cases of diabetic patients and 110 healthy control group .and we also detected thevalue of serum creatinine (Scr),urinary creatinine (Ucr),and calculated creatinine clearance rate (Ccr),compared the correlation of Cys C,RBP with Ccr,Scr.Results The contents of serum Cys C,RBP in the group of diabetic nephropathy were significant higher than that in healthy controllers(P<0.01),and Cys C,RBP were significantly negative correlation with Ccr.Conclusion The sensitivity and accuracy of the combined determination of serum Cys C,RBP in diabetic nephropathy are improved and might provide valuable proof for early diagnostic in diabetic nephropathy.