Objectives To investigate the expression and clinical significance of HOXA10 gene in the eutopic and ectopic endometrium of endometriosis.Mehtods Between Jan.2009 to Aug.2010,30 patients with endometriosis undergoing laparoscopic surgery in Maternal and Children's Hospital of Foshan.Eutopic and ectopic endometrium were obtained.In the mean time,30 patients with benign ovary cyst or tubal infertihty undergoing laparoscopic surgery were selected as controls.Their uterine endometrium were obtained real-time fluorescent quantitation,western blot and immunohistochemistry technique were used to detect mRNA and protein expression of HOXA10 gene in the eutopic endometrium group,ectopic endometrium group and control group.Results The mRNA and protein expression of HOXA10 gene were 0.61 ±0.07 and 0.47 ±0.05 in the eutopic endometrium of endometriosis,0.64 ±0.06 and 0.50 ±0.05 in ectopic endometrium of endometriosis,which were significantly lower than 1.22 ± 0.14 and 1.42 ± 0.14 in control group ( P ＜ 0.01 ).However,the mRNA and protein expression of HOXA 10 between eutopic and ectopic endometrium of endometriosis did not reach statistical difference ( P ＞ 0.05 ).The expression of HOXA10 in eutopic and ectopic endometrium of endometriosis were decreased by immunohistochemistry staining.Conclusion The lower expression of HOXA10 gene in the eutopic and ectopic endometrium of endometriosis might be associated with pathogenesis and infertility of endometriosis.