Abstract: Objective：To study the clinicle value of hysteroscopy in diagnosis and treatment of oblique vaginal septum syndrome. Methods：13 patients（7 cases of typeⅠ，1 cases with congenital urethrovaginal fistula，6 cases of type Ⅲ，Ⅱ） with oblique vaginal septum syndrome（OVSS） are enrolled from 2003 January to 2011 December. A systematic retrospective analysis，age 11-20 years old，average age is 13.6±2.8 years old，with abdominal pain after menarche，periodic abdominal pain or a pelvic mass was detected on admission，preoperative hysteroscopy combined with ultrasonography can make clear the clinical diagnosis. Hysteroscopy can find total reproductive development，guide and locate the septum position. Incision and resection of oblique vaginal septum，removal of vaginal or intrauterine hematocele or empyema. Results：Postoperative dysmenorrhea symptom disappeared，the volume no change，no vaginal or abdominal mass happened again. Conclusions：In diagnosis of oblique vaginal septum, hysteroscopy is an important means， combined with ultrasound examination to clearly understand reproductive development and localize of oblique vaginal septum position，guide operation resection or clear cut parts. By hysteroscopy and ultrasonography can make oblique vaginal septum operation more accurate，safe，fast，and direct.

Key words: Vagina, Congenital abnormalities, Hysteroscopy, Retrospective studies, Diagnosis, Therapy