Abstract: 　Objective　To investigate the significance of serum catalase (CAT), paraoxonase (PON) and malondialdehyde (MDA) in children with Henoch-Sch?nlein purpura (HSP). Methods A total of 47 children with HSP were selected from April 2009 to October 2011, meanwhile 20 healthy children were selected as normal controls. The serum CAT, PON, MDA were detected and compared between two groups, and the association of CAT, PON and MDA levels with urine protein levels were analyzed in children with HSP. Results In children with HSP, the levels of CAT and PON were significantly lower and MDA levels were significantly higher than those in the control group (P<0.05). HSP patients with hematuria or proteinuria had significantly lower levels of CAT and PON than those without hematuria or proteinuria, while HSP patients with proteinuria have significantly higher level of MDA than those without proteinuria (P<0.05). In children with HSP, the serum levels of CAT and PON were negatively correlated with urine protein levels (r=-0.674, -0.647, P<0.05) while MDA level was positively correlated with urine protein levels (r=-0.659, P<0.05). Conclusions The levels of CAT and PON were decreased and MDA was increased in children with HSP, and so they can be used to evaluate the severity of nephropathy.