Abstract: Objective：To explore the diagnosis and treatment of antepartum mastitis.Methods：The clinicopathological，operative and followup data of 23 cases of antepartum mastitis were retrospectively analyzed.Results：The clinical and pathological data of all the 23 patients were complete.All patients had received core biopsy in the outpatient department.Among the 14（60.8%）patients treated with antibiotics alone，4（17.4%）patients had complete response after antibiotic treatment，6（26.1%）patients had abscess  during treatment，2（8.7%）patients had no significant remission，and 2（8.7%）patients underwent radical surgery after symptom aggravation.Abscess formation was found in 9（39.1%）patients at the initial diagnosis，and a total of 15（65.2%）patients underwent abscess incision and drainage with small incision.Postoperative complications such as hemorrhage and recurrent infection were not found in any patients.All patients gave birth normally，without premature birth，abortion，overdue birth，deformed baby，etc.，and the fetus was healthy.The patients were followed up for 2 years，and no recurrence was found.Conclusion：Prenatal mastitis patients，need to consider the safety of the fetus，according to the condition of the choice of the least damage，the best therapeutic regimen.

Key words: antepartum mastitis, pregnancy, nonlactating mastitis