Abstract： Objective： To observe the clinical effect of modified Yanghe tang combined prednisolone forplasma cell mastitis. Methods：A total of 73 cases of patients with plasma cell mastitis were randomly divided into the treatment group and the control group， with 38 and 35 cases in each group respectively. Both groups were treated with tinidazole for anti infection，and those with abscess were treated with surgical resection. The control group was treated with prednisolone on this basis，and the treatment group was treated with modified Yanghe tang on the basis of the control group.The symptoms of breast pain，changes of skin in breast mass，and levels of prolactin(PRL) in serum before and after treatment as well as clinical effects and recurrence rates in the two groups were compared. Results：The total effective rate was 94.74% in the treatment group and 74.29% in the control group，the difference being significant(P＜0.05). After 12-month follow-up，the total recurrence rate was 5.26% in the treatment group and 25.71% in the control group，the difference being significant(P＜ 0.05). After treatment， the scores of breast pain in the two groups were decreased when compared with those before treatment(P＜0.05)，and the score of breast pain in the treatment group was lower than that in the control group(P＜0.05). After treatment，the scores of changes in skin of breast mass in the two groups were decreased when compared with those before treatment(P＜0.05)， and the score in the treatment group was lower than that in the control group(P＜0.05). After treatment， the PRL levels in serum in the two groups were decreased when compared with those before treatment(P＜ 0.05)， and PRL level in the treatment group was significantly lower than that in the control group(P＜0.05). Conclusion： Modified Yanghe tang combined prednisolone has a significant curative effect in treatingplasma cell mastitis， which can effectively relieve breast pain，improve skin of breast mass and reduce PRL secretion levels with low recurrence rates.