Objective To investigate re-innervation in the neovaginal mucosa of patients underwent sigmoid colon vaginoplasty in treatment of Mayer-Rokitansky-Kistner-Hauser Syndrome (MRKHS).Methods Biopsies in the upper third of the posterior neovagina were taken in 20 patients treated by sigmoid colon vaginoplasty at 1, 2 and 3 years after surgery, respectively. Protein gene product 9. 5 ( PGP 9. 5 ),vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) were detected by immunohistochemical method and compared with those in intact sigmoid colon mucosa. Results ( 1 ) Density of nerve fiber:abundant distribution of PGP 9. 5 nerve fibers were observed in the mucosal muscle layer, submucosa, and smooth muscle layer of the neovagina. The nerve fibers of VIP and NPY immunoreactivity were mainly distributed around blood vessels and in the smooth muscles. In the neovagina, the density of nerve fibers of PGP 9. 5 of 17 ± 6 were much more than VIP of 2. 9 ± 1.0 and NPY of 2. 5 ± 0. 8 significantly ( P ＜ 0. 05 ).( 2 ) Expression of PGP 9. 5 in neovagina: at 1 year after surgery, PGP 9. 5 positive expression of 14 ± 4 was significantly lower in the neovagina than 28 ± 7 in the intact sigmoid colon( P ＜ 0. 05 ). However, after 2 to 3 years, its expression displayed an upgrade tendency in the neovagina and was significantly higher at the 3 year postoperatively than that at the 1 years postoperatively ( 22 ± 7 vs. 14 ± 4, P ＜ 0. 05 ). The changes were much more obvious in submucosa. (3) The expression of VIP and NPY in neovagina: at 1 year after surgery, VIP and NPY positive nerve fibers were also decreased in the neovagina when compared with those in the intact sigmoid colon ( 2. 3 ± 0. 7 vs. 5.3 ± 1.4, P ＜ 0. 05; 2.5 ± 1. 1 vs. 5.5 ± 1.1, P ＜ 0. 05 ) . At 2 to 3 years after surgery, the positive VIP fiber showed initially decreased and subsequently increased tendency. The density of VIP of 3.7 ± 0. 7 in the neovagina at 3 years postoperatively was higher than 2. 3 ±0. 7 at 1 years postoperatively (P ＜ 0. 05 ). No significant up-regulation was observed in NPY-positive expression in the neovagina within 3 years after operation. Conclusions Distribution of sensory PGP 9. 5,VIP and NPY immunoreactive nerve fibers was similar to the pattern observed within the intact sigmoid colon wall. The number of nerve fibers in the neovagina decreased after surgery and then increased subsequently within 3 years after surgery.