Abstract: 【Abstract】 Objective To determine the value of conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) in the diagnosis of placenta residue with implantation. Methods We retrospectively analyzed 112 cases of placenta remnants from Apr. 2013 to Mar. 2016, all of which were confirmed by pathological results. The cases were divided into implanted (n =74) and non-implanted (n =38) groups. We compared the characteristics of US and CEUS imaging between the two groups. Multi-variate logistic regression models were established to assess the accuracy of ultrasound imaging in predicting implantation, including the area under the curve (AUC ) of receiver operating characteristic (ROC) curves. Results US detected intrauterine lesions, with significant differences between the two groups in the clearness of boundaries of lesions (P <0.05) . Differences between the two groups were also found in CEUS in enhanced phase, enhanced intensity, existence of clear and regular boundaries, and reduced muscle thickness in the lesion area (P <0.05). CEUS (91.1%) and US+CEUS (92.0%) had a higher prediction accuracy for placenta implantation compared with US (87.5%) (P <0.05). The AUC of CEUS (0.922) and US+CEUS (0.952) were also significantly higher than that of US (0.887) (P <0.05). No significant differences were observed between CEUS and US+CEUS. Conclusion The value of CEUS for predicting placenta implantation is higher than US.