Objective To investigate the changes of urinary brush border membrane enzymes and serum cystatin C (Cys C) in newborns in order to develop early diagnostic indicators for sclerema neonatorum (SN) renal dysfunction.Methods Sixty-night cases with sclerema neonatorum and 30 cases of normal newborns were enrolled in this study.Of all sclerema neonatorum cases,39 cases were mild and 30 cases were moderate to severe sclerema neonatorum.Immunoca talytic assay method was adapted to detect the level of urinary brush border membrane.The levels of serum Cys C,blood urea nitrogen (BUN),creatinine (Cr) and urinary β32 microglobulin (β2-MG) in two groups were also measured.Results The levels of urinary brush border membrane enzyme,β2-MG and serum Cys C in sclerema neonatorum group were (40.09 ± 7.29) U/L,(4.65 ± 1.33) mg/L and (1.84 ± 0.32) mg/L,higher than those in control group ((23.19 ± 5.62) U/L,(2.49 ± 0.77) mg/L and (1.07 ± 0.25) mg/L; t =10.34,7.47 and 10.55,P ＜ 0.01).The levels of urinary brush border membrane enzyme and serum Cys C in moderate to severe sclerema neonatorum group were (42.06 ± 7.59) U/L and (1.93 ± 0.34) mg/L,higher than those in the mild group ((38.57 ± 6.70) U/L,(1.77 s0.29) mg/L;t =2.24,2.11,P ＜0.05).The abnormality rates of urinary brush border membrane enzyme and serum Cys C in sclerema neonatorum group were 79.7％ (55/69) and 72.5％ (50/69),higher than β2-MG abnormal rate (52.2％ (36/69),x2 =12.95,12.11,P ＜ 0.01).In sclerema neonatorum group,urinary brush border membrane enzyme was positively correlated with β2-MG (r =0.560,P ＜ 0.01),and serum Cys C was positively correlated with BUN,Cr (r =0.314,0.287,P ＜ 0.05).Conclusion Renal injury is common in SN.Urinary brush border membrane enzyme and serum Cys C are served as the diagnostic parameters for early detection of renal injury in SN.