【Abstract】 Objective To investigate the clinical value of ultrasound guided Mammotome elite biopsy in the diagnosis and treatment of abscess stage of plasma cell mastitis.Methods 40 paitents of abscess stage of plasma cell mastitis were biopsy with Mammotome elite under Ultrasound guided. Low echo area was punctured and tissues were sent to pathological examination. After that, no echo area was punctured and most of the pus which was sent to bacteria culture and drug sensitivity was extracted. After the puncture, normal saline was injected to the abscess cavity through the cut by Mammotome elite. After the pathological diagnosis of plasma cell mastitis, traditional Chinese medicine Wenyang Tongluo recipe was given for treatment. The complications were observed before and after puncture, and the size of the abscess cavity and mass were recorded.Results 40 cases were successfully treated with no obvious adverse reaction and all were by the pathological diagnosis of plasma cell mastitis. The average size of the 40 patients’abscess cavity was decreased after biopsy and the difference was statistically significant（P＜0.05）.The average size of the mass was not significantly changed after the puncture（P＞0.05）. The pus in 2 patient was fostered the growth of staphylococcus aureus and the pus in 1 patient was fostered the growth of anaerobe, while other 37 cases of patients with pus bacterial culture showed no bacterial growth. The patients were given Wenyang Tongluo recipe in treating after biopsy. All were clinical cured and the average duration was 87 days.Conclusion Ultrasound guided Mammotome elite biopsy with high rate of accuracy in diagnosis is simple and safe. Diagnosis at the same time adequate drainage to abscess cavity can be made. After full drainage, Wenyang Tongluo recipe is effective in the treatment of abscess stage of plasma cell mastitis, and can be used in clinical application.