Study Subjects: Eligible patients were initially diagnosed with chronic endometritis (CE) by CD138 testing through outpatient hysteroscopy. Positive CD138 expression is defined as at least one or more positive-staining plasma cells per 10 high-power fields identified as positive, and less than one positive-stained plasma cell identified as negative \[8\]. All patients signed an informed consent form prior to participating in the study, and the study followed the principles of the Declaration of Helsinki. Inclusion Criteria: Diagnosis of chronic endometritis by CD138 immunohistochemistry; Age≥ 20 years old, females of childbearing age; Agree to undergo hysteroscopy and hysteroscopic endometrial biopsy; No serious systemic disease; There are no contraindications to oral administration of doxycycline hydrochloride and berberine hydrochloride. Exclusion criteria: patients with pregnancy status, uterine malignant disease, hormone therapy within 3 months, glucose-6 phosphate dehydrogenase deficiency, hemolytic anemia, hypersensitivity to berberine hydrochloride or doxycycline. In addition, berberine hydrochloride has fewer oral adverse reactions, occasional nausea and vomiting, rash and drug fever, which disappear after stopping the drug. If the patient takes the wrong or missed medication, it is excluded. Withdrawal criteria: If the patient has corresponding adverse reaction symptoms, those with mild symptoms can be temporarily observed, and if the symptoms are severe, they can be transferred to the Department of Gastroenterology for diagnosis and treatment, and those who need to stop the drug will be withdrawn from this study.