Objective Transperineal three-dimensional ultrasonography combined with real-time shear wave elastography (SWE) was used to quantitatively evaluate the changes in the hiatus area of the levator ANI muscle and the elasticity of the puborectalis muscle (PR) in primipara and childless women，To investigate the effect of pregnancy and delivery on the laceration of levator ANI muscle, PR elasticity and contractile function. Materials and Methods 50 primiparas who came to the Liutie center Hospital of Liuzhou City to examine at postpartum 6-8 weeks from December 2017 to January 2018 were enrolled, At the same time, 41 healthy nulliparous women were selected as the control group. Three dimensional transperineal ultrasound was used to measure the hiatus area of levator ANI muscle under resting and maximum contraction state, and the hiatus area of levator ANI muscle in the two groups was compared.The Young’s. modulus of PR was measured with SWE at resting-state and during maximal contraction respectively. Differences of PR elasticity and contraction function in the 2 groups were compared. Results. The hiatus area of the levator ANI muscle in the postpartum group under the resting state and the maximal anal retraction state was larger than that in the control group, and the difference was statistically significant (P<0.05).The elasticity parameters of spontaneous vaginal delivery group were less than those in the control group. The difference was of statistical significance (P<0.05).Conclusion Pregnancy and vaginal delivery have certain damage to the elasticity and contractility of PR.