Objective: MRI changes of pubic symphysis injuries of primiparas and its relationship with pubic symphysis pain and mode of delivery. Methods: 20 primiparas with MRI, were divided into cesarean, normal vaginal delivery and high-risk vaginal delivery. MR changes were observed. Results : pubic symphysis fibroadenoma avulsion was significantly correlated with pubic symphysis pain. Width of pubic symphysis of the primiparas was wider. primiparas had pubic bone marrow edema, which was not associated with pubic symphysis pain. 1 case pubic fracture. MRI changes were not associated with mode of labor. Conclusion: The severy pubic symphysis pain may be related to the symphysis pubis fibrocartilage avulsion and was not related to the pubis bone marrow edema.