Objective To investigate MRI in identifying different types of placenta previa and the sensitivity of placenta implantation. Methods The clinical data of 24 patients with placenta previa confirmed by clinical operation and postoperative pathology from August 2012 to August 2014 were retrospectively analyzed. All of the patients underwent MRI routine. The diagnostic results and MRI imaging findings were summarized. Results Subject to clinical operation and postoperative pathology, The coincidence rates of MRI in the diagnosis complete placenta previa, part placenta previa and marginal placenta previa were 93.33%, 75.0% and 100.0%, respectively. The imaging findings showed that the placenta tissues covered the entire or part internal opening of the cervix, or at the edge of the internal opening of the cervix. The coincidence rates of MRI in the diagnosis of adhesive type, implantable type and penetrating placenta implantation were 100%, 75.0% and 66.67%, respectively. The diagnostic sensitivity was 78.57% and the specificity was 80.0%. The imaging findings showed that the placenta-uterine boundaries were interrupted or continuous, the placenta was thickened, the morphology was abnormal and the internal signal was also abnormal. The placenta-uterine boundaries were interrupted or obscure. Conclusion MRI can define the type of placenta previa and placenta implantation and has high application value