Abstract: Objective：To explore the relationship between the dysfunction of pelvic floor in primipara and the expression of elastin、collagen、fibulin-5 and TGF-β in vaginal wall. Methods：The subjects composed of primipara delivered in Maternal and Child Health Care Center of Jiading District，without complications of hypertention，GDM，FGR and fetal macrosomia，aged 20-30 years. The study group，women with SUI and Ⅰ or Ⅱ degree prolapse of anterior vaginal wall by POP-Q and the control group，women without SUI or prolapse of vaginal wall，were investigated. Vaginal wall specimens were obtained during the vaginal delivery after lateral episiotomy. Tissues were detect by Masson stainning to compare the difference of elastin and collagen while expression level of fibulin-5 and TGF-β by immunohistochemistry. Results were analysed by Image-Pro Plus software and Student′s t-test as statistical method. Results：Expression of fibulin-5 were higher in the control group than in the study group （t=3.062，P=0.005），while TGF-β had no statistical difference between them （t=1.670，P=0.098）. Elastin and collagen were abnormal between the two groups by Masson staining，regular，intact in the control group while disorder，fracture in study group. Conclusions：The dysfunction of pelvic floor in pregnancy period may be caused by the decreased expression of elastin and fibulin-5 which is the crosslink factor of elastin.

Key words: Urinary incontinence, stress, Fibrillar collagens, Transforming growth factor beta, Pelvic floor dysfunction, Pelvic organ prolapse