Abstract: Objective To evaluate the value of prenatal ultrasonography in diagnosis of placenta accreta in patients with placenta pracvia. Methods A total of 87 pregnant women with placenta previa undergoing cesarean section I our Department from March, 2009 to June, 2016 were enrolled into this study.The two-dimensional ultrasound and color Doppler ultrasonography were performed in all patients.The patients were divided into placenta accrete group and non-accrete group according to the postoperative pathological results.The ultrasonographic features of the two groups were compared.The sensitivity, specificity, missed diagnosis rate, misdiagnosis rate and Kappa value of prenatal ultrasound for the placenta accrete were evaluated. Results Among 87 cases of placenta previa, the incidence of thickened placenta, disappearance of part or all of the posterior placental space, myometrial thickness that placenta attached to, placenta internal uneven echo, well vascularized uterine serous layer-bladder interface that placenta attached to, focal or generalized placental parenchyma lacunae blood flow in the placenta accrete group was significantly higher than that of non-accrete group (P < 0.05).There was no significant difference in the type of placenta previa between placenta accreta group and non-accrete group (P >0.05).Taking pathological results as the gold standard, the sensitivity of preimplantation ultrasound was 80.00%, specificity was 91.23%, missed rate was 20.00%, misdiagnosis rate was 8.77%, and Kappa was 0.718. Conclusion Prenatal ultrasound examination for placenta accreta in patients with placenta previa has a high sensitivity and specificity, which can provide guidance for safe delivery.