[Abstract] Objective To explore the correlation between SUI after delivery and levator trauma with 3D pelvic ultrasound. Methods Patients suffered from SUI after delivery, the POP patients and the normal ones that meet standards were selected to test anteroposterior diameter, transverse diameter and areas of levator, also to observe morphology of levator and muscles around it with 3D pelvic ultrasound combined TUI under quiescent condition and after Valsalva movement, then analyse statistically with these data. Results patients suffered from SUI have no significant difference in anteroposterior diameter and transverse diameter under quiescent condition compared to the other two groups, but significantly changed after Valsalva movement. The areas of levator are obviously bigger in group of patients suffered from SUI than the other two groups no matter under quiescent condition or after Valsalva movements. Also, the ratio of levator laceration is higher in SUI group than the other two groups when Observed With TUI. Conclusions The areas changes and laceration of levator have explicitly correlated to occurrence of SUI.