Abstract：Objective：To observe the clinical effect of modified Yigong powder combined with conventional treatment for antibiotic associated diarrhea(AAD) in children. Methods： A total of 108 children with syndrome of deficiency- cold of the spleen and stomach were randomly divided into the control group and the observation group，54 cases in each group. Both groups were given measures to prevent the imbalance of water，electrolyte，acid and base，and nutritional support，and were given bifidobacterium trifecta powder， montmorillonite powder and pitomod granule； the observation group was additionally treated with internal administration of modified Yigong powder. The treatment course of both groups was seven days. The Chinese medicine syndrome score was assessed before and after treatment，and the stool frequency and shape of the children every day were recorded， and the stool frequency less than three times and the stool forming time were recorded. The children who were in a better condition but had worse symptom of diarrhea again seven days after treatment were recorded， and the recurrence rate was calculated. Results： After treatment， the therapeutic effect of disease and Chinese medicine syndrome in the observation group were better than those in the control group(P＜0.05). The scores of stool frequency， stool shape and syndrome after treatment in the two groups were all decreased when compared with those before treatment(P＜0.01)， and the above scores after treatment in the observation group were lower than those in the control group(P＜0.01). The stool frequency less than three times and the forming time of defecation in the observation group were faster than those in the control group(P＜0.01). Within seven days after treatment，the recurrence rate was 7.84% in the observation group and 23.81% in the control group，the difference being significant(P＜0.05). Conclusion：The therapy of modified Yigong powder combined with conventional treatment for AAD children with syndrome of deficiency- cold of the spleen and stomach can effectively relieve symptoms，shorten the course of disease，reduce the recurrence rate，and has accurate clinical effect.