Abstract：Objective：To observe the clinical effect of modified Tongluo Huayu prescription for lymphedema of affected limbs after operation for breast cancer. Methods： A total of 82 cases of patients with lymphedema of affected limbs after radical mastectomy were selected as the study subjects and divided into the treatment group and the control group according to the random number table method， 42 and 40 cases in each group respectively. The control group was given routine treatment in western medicine，and the treatment group was additionally treated with modified Tongluo Huayu prescription based on the treatment of the control group. The clinical effect in the two groups were compared. Before and after treatment， the perimeter of affected limbs， the improvement of symptoms in affected limbs and the upper limb function in the two groups were compared. Results： The total clinical effective rate was 92.86% in the treatment group， higher than that of 70.00% in the control group(P＜0.05). After treatment， the arm circumference， the subjective symptom scores including numbness，pain，swelling and heaviness in affected limbs as well as the scores of Disabilities of the Arm，Shoulder，and Hand questionnaire(DASH) in the two groups were decreased when compared with those before treatment(P＜0.05)； the arm circumference，the subjective symptom scores including numbness，pain，swelling and heaviness in affected limbs as well as the DASH score in the treatment group were lower than those in the control group(P＜0.05). Conclusion：Modified Tongluo Huayu prescription has definite curative effect in treating patients with lymphedema of affected limbs after operation for breast cancer， and can significantly decrease the perimeter of affected limbs， relieve the symptoms of swelling in affected limbs and improve upper limb function.