Abstract: Objective: To explore the correlation between the serum level of neutrophil gelationase associated lipocalin(NGAL) in type 2 diabetes mellitus(T2DM) and early diabetic kidney disease(DKD).Methods: A total of 95 patients with T2DM were divided into the normal albuminuria group(NA group,UAER<20 μg/min,n=25),microalbuminuria group(MA group,20 μg/min ≤ UAER<200 μg/min,n=30),and clinical albuminuria group(CA group,UAER ≥ 200 μg/min,n=40),and 39 healthy volunteers were set as normal control group.The serum NGAL levels in all cases were measured by ELISA,and the correlations between NGAL and sCr,BUN,CysC and eGFR were analyzed.The sensitivity of serum NGAL in early diagnosis of DKD was evaluated using receiver operating characteristic(ROC) curve.Results: The levels of serum NGAL in NA,MA,and CA groups increased compared with control group(P<0.01),which in CA group was the highest(185.65±61.76)ng/mL.Spearman analysis showed that the serum NGAL level was positively correlated with the levels of BUN,sCr and CysC (r_s=0.395,0.408 and 0.257,respectively,P<0.05 to P<0.01),and the serum NGAL level was negatively correlated with the levels of eGFR and Alb,respectively(r_s=-0.328 and -0.430,respectively,P<0.01).The UAER>20 μg/min was set as critical point,the area of serum NGAL and CysC under ROC curve in MA group and CA group were 0.675 and 0.789,respectively.Conclusions: The serum NGAL level is related to the levels of BUN,sCr,CysC and eGFR in early DKD patients,and the NGAL may be a sensitive indicator in the early diagnosis of DKD.