Objective To investigate the clinical effect of combined treatment of children allergic purpura with traditional Chinese and western medicine and preventive effect on renal damage ,and provide the basis for clinical therapy.Methods According to the different treatment methods ,96 children with allergic purpura were divived into the treatment group and the control group ,each group in 48 cases.The treatment group treated by combined western and Chinese medicine ,the control group was treated with western medicine ,the symptoms disappear time observation of treatment of the two groups of children,urinary N -acetyl -D beta glucosidase(NAG),urine albumin(mALB) changes,compared two groups of children with renal damage occurrence time and the incidence .Results The treat-ment group purpura disappearance time ,joint pain and swelling disappeared time ,abdominal pain disappeared time were (5.15 ±2.26)d,(3.12 ±0.81) d,(2.06 ±0.16) d,the control group respectively were (8.03 ±3.08) d, (5.13 ±1.09)d,(4.76 ±1.04)d.The difference between the two groups had statistical significance (t =2.01, 11.03,24.54,all P<0.05);After three months of treatment,the treatment group abnormal urine rate,NAG,mALB were 16.7%,(5.46 ±3.20) u/L,(7.24 ±7.62) mg/L,the control group were 37.5%,(7.58 ±4.32) u/L, (19.40 ±3.48)mg/L,the difference between the two groups was statistically significant (χ2 =6.67,t=2.72,10.13, all P<0.05).The treatment of renal damage occurred time [(36.4 ±12.4) d] later than that of the control group [(22.1 ±10.6)d](t=6.08,P<0.05),the incidence of renal damage in treatment group (16.7%) was lower than that in the control group (41.2%) (χ2 =7.26,P<0.05).Conclusion Compared with simple western medicine treatment,the treatment of children allergic purpura with combination of TCM and western medicine can reduce the symptoms disappeared time,reduce the content of NAG,mALB,reduce the incidence of renal damage ,and prevent kidney damage .