Abstract: Objective：To investigate the clinical value of intravenous contrast-enhanced ultrasound（CEUS） in uterine cesarean scar pregnancy. Methods：The CEUS were performed in 20 cases of suspected pregnancy within uterine cesarean. Contrast agents were the second generation of acoustic contrast agent SonoVue made in Italian Bracco company. The agents appearance and disappearance time and intensity in the leision，perfusion pattern and the relationship between lesion and serosa layer/muscular layer，were observed. Results：The lesions types can be divided into gestation sac type and mass type. The CEUS shows that high intensity and fast accumulation of contrast agents are observed in cesarean leisions，compared with myometrium nearby. Contrast model is fast entrance and slow disappear；The CEUS can also identify the integrity of serosal layer and muscular layer，and the intrusion or not of the lesion to the muscular layer , even serosal layer，while the 2D-ultrasound can not distinguish the verge of leisions and muscular layer. Conclusions：The CEUS can give more important diagnositic information in caesarean scar pregnancy ，and guide clinical treatment followed.

Key words: Cesarean scar pregnancy, Contrast-enhanced ultrasound, Contrast agents, Cesarean delivery