To evaluate the value of transvaginal three-dimensional ultrasound in endometrial receptivity (ER) in patients with adenomyosis (AM). Methods Forty-five patients diagnosed with AM in our hospital from June 2021 to January 2022 were prospectively studied as AM group, and thirty-four healthy postpartum women were selected as the control group. Two-dimensional and three-dimensional ultrasound examinations were performed in the middle luteal phase. Endometrium thickness, echo types, blood flow grade, endometrial and subendometrial volume, endometrial and subendometrial vascularization index (VI), flow index (FI), vascularization flow index (VFI) were compared between the two groups. The morphology of uterine junctional zone (JZ) was observed on the coronal plane of the uterus by transvaginal three-dimensional ultrasound. The maximum thickness (JZ max), minimum thickness (JZmin), difference between maximum and minimum thickness (DJZ) and average thickness (MJZ) of JZ were measured.Results There were no significant differences between AM group and control group in age, two-dimensional ultrasound indexes (endometrial thickness, echo type, blood flow grade) and some three-dimensional ultrasound indexes (endometrial and subendometrial volume, endometrial and subendometrial VI, FI, VFI) (P＞0.05). The JZ in AM patients was irregular in shape, and the thickness difference was large. JZmax and DJZ in AM group were higher than those in control group, JZmin in AM group was lower than that in control group, and the differences were statistically significant (P＜0.05). There was no significant difference in MJZ between the two groups. Conclusion Transvaginal threedimensional ultrasound has important value in evaluating ER in AM patients, and can provide imaging basis for clinical diagnosis and treatment of infertility symptoms in AM patients. Among them, threedimensional ultrasound indicators that need special attention include JZ max, JZmin and DJZ on the coronal plane of uterus after three-dimensional reconstruction