Abstract: Objective:To explore the sensitivity and specificity of normal testing indexes in the diabetic patients whose hemoglobin A1c(HbA1c) abnormal with early renal damage.Methods:Group were divided according to urinary protein qualitative,group A was negative,group B was trace to 1 +,group C was 2 + to 3 +.Urinary protein(IgG,TＲF,mALB,1-m,2-m) were detected by using immune nephelometry method; serum Cys C,BUN and Cr were detected by using the methods of circulatory enzyme,enzyme and picric acid electrode respectively.Results:Each testing index in three groups of diabetes had differences in general(P 0.01),the positive rate of urinary protein of(IgG,TＲF,mALB,2-m and mALB/Cr) in group A was lower than that in group B and C(P 0.05),but 1-m,Cys C,BUN,Cr were lower than that in group C(P 0.05-P 0.01).There were no significant differences between group B and C in each testing indexes(P 0.05).The positive rate of all indexes had significant differences in the group of diabetic and control(P 0.01).The positive rate of IgG,TＲF,2-m,mALB,mALB/Cr in diabetes with negative urine protein was higher than that in control group(P 0.05).There was no significant difference in specificity(P 0.05).Conclusions:As a testing indexes,TＲF,mALB,2-m,mALB/Cr will be more sensitive and specific when compared with other indexes in detecting early diabetic renal damage whose HbA1c is positive and urinary protein qualitative is negative.They can be using to screen early diabetic renal damage alone or combination.