Objective To improve the detection rates of cesarean scar pregnancy, the transvaginal ultrasound (TVS) features of cesarean scar and cesarean scar pregnancy were analyzed. Methods 915 patients who had a history of abortion for more than six months and were suspected pregnancy intended artificial termination of pregnancy or suspected incomplete abortion intended curettage were reviewed retrospectively;and the TVS performances of cesarean scar, the relationship between gestational sac and cesarean scar , the ultrasound characteristics of uterine scar pregnancy of 17 cases were analyzed . Results 860 cases of uterine scar healed well; 38 cases of uterine scar formation of diverticula; 649 cases of uterine scar normal part of pregnancy; 17 cases of uterine scar pregnancy, included 15 gestational sac type and 2 abnormal sonographic mass;the first type included 9 cases of superficial implantation type and 6 cases of deep implantation type. Conclusion TVS can better observe and evaluate healing after caesarean section, diagnose scar pregnancy earlier, prevent inappropriate abortion and pregnancy.