Objective:To investigate the feasibility and influencing factors of ultrasound-guided transabdominal core needle biopsy for adenomyosis before microwave ablation.Methods:From September 2020 to August 2023,40 patients who received transabdominal ultrasound-guided microwave ablation therapy and core needle biopsy for adenomyosis in our hospital were en-rolled in this retrospective study.Prior to the ablation,a transabdominal core needle biopsy using a 16G automatic biopsy needle was performed under ultrasound guidance to obtain histological specimens.According to the results of histopathological diagnosis,patients were divided into two groups:pathological diagnosis consistent group and pathological diagnosis inconsistent group.The pathological diagnosis coincidence rate of biopsy for uterine adenomyosis was calculated,and its related influencing factors were analyzed.Results:An average of 1.15(1~3) time of biopsies were performed on these patients,with a success rate of 100% for biopsy sampling.Among them,the pathological diagnosis coincidence rate of biopsy was 70.0%(28/40).Comparing the results between pathological diagnosis consistent group and pathological diagnosis inconsistent group,the pathological diag-nosis inconsistent group had shorter specimen length(P=0.016),smaller uterine volume(P=0.048),and a lower proportion of ul-trasound characteristic structures hit in the puncture biopsy area(P=0.018),with statistical significance.Conclusion:Ultrasound guided transabdominal core needle biopsy before microwave ablation of adenomyosis is a simple,safe,and effective way to obtain pathological diagnosis.