Abstract：Objective：To observe the effect of the therapy of modified Dahuang Mudan tang combined with amoxicillin and clavulanate potassium on patients with lymphedema secondary to lower limb erysipelas. Methods： A total of 320 cases of clinical data of patients with lymphedema secondary to lower limb erysipelas of dampness- heat toxin accumulation type were retrospectively selected and divided into the experiment group and the control group according to the different treatment，with 160 cases in each group. Both groups were treated with intravenous infusion and oral sequential therapy of amoxicillin and clavulanate potassium. The experiment group was additionally treated with external application of modified Dahuang Mudan tang， and the control group was additionally treated with external application of Chloramphenicol borate solution. Both groups were continuously treated for two cycles，seven days being a cycle. Before and after two cycles of treatment， the Chinese medicine syndrome scores， white blood cell count， neutrophil count， C- reactive protein(CRP) and differences of the circumference of lower limbs were compared. The clinical effects， swelling degree of lower limbs and incidence of adverse reactions were compared between the two groups. Results：After two cycles of treatment，the total clinical effective rate was 92.50% in the experiment group， higher than that of 85.63% in the control group， the difference being significant(P＜0.05). The Chinese medicine syndrome scores in the two groups were lower than those before treatment， and the Chinese medicine syndrome scores in the experiment group were lower than that in the control group，differences being significant(P＜0.01). The erythema and swelling degree of lower limbs in the experiment group was better than that in the control group(P＜0.05). The levels of white blood cell count，neutrophil count and serum CRP in the two groups were decreased when compared with those before treatment，and the differences of circumference of lower limbs were decreased，differences being significant(P＜0.01). The above four indexes in the experiment group were lower than those in the control group， differences being significant(P＜0.01). There was no significant difference being found in the comparison of the incidence of adverse reactions between the two groups(P＞0.05). Conclusion： The therapy of modified Dahuang Mudan tang combined with amoxicillin and clavulanate potassium can effectively reduce the clinical symptoms and swelling degree of lower limbs in patients with lymphedema secondary to lower limb erysipelas of dampness- heat toxin accumulation type， reduce the inflammatory responses，and significantly improve the clinical effect.