【Abstract】 Objective To investigate the clinical diagnostic value of magnetic resonance imaging (MRI) to prenatal placental abnormality of late pregnant women. Methods 41 gravidas aged from 22 to 41 years old with the mean age of 29 and mean gestational weeks of 35 were enrolled to this study. Suspicious placental abnormality had been reported after clinical or ultrasound diagnosis for all pregnant women, which received the MRI examination including 2D FIESTA, DWI, LAVA, and T1WI sequences. Conventional scan on transverse plane, sagittal plane of the uterus, and coronal plane of the pregnant women were performed. The comparison between the prenatal MRI representation and the surgical results were also conducted. Results Placental abnormality was observed in fortyone pregnant women. The abnormality included 1 cases of placenta adhesion, 30 cases of praevia placenta, 31 cases of placental invasion, 3 cases of ablatio placentae with hematoma, and 1 case of placental hemorrhage. The praevia placenta also included 5 cases of low implantation of placenta, 4 cases of marginal previa placenta, 6 cases of partial previa placenta, and 15 cases of total previa placenta. The ablatio placentae and hematoma contained 2 cases of dorsal placental detachment and 1 case of dorsal and under amniotic ablatio placentae with hematoma. Thirty five prenatal placental abnormalities just were observed from ultrasound examination. Conclusion MRI is greatly valuable for the diagnosis of prenatal placental abnormality to advanced pregnant women.