Abstract： Objective To evaluate the factors associated with clinical pregnancy rate of in-vitro fertilization (IVF) in endometriosis related infertility.Methods Total of 326 patients with endometriosis related infertility undergoing IVF between January 2007 and December 2011 were studied in Department of Reproductive Medicine,First Affiliated Hospital,Nanjing Medical University,retrospectively,which were divided into 141 cases in clinical pregnancy group and 185 cases in non-pregnancy group.Those factors including age,body mass index (BMI),basic FSH,antral follicle count (AFC),CA125 and CA199,endometriotic stage and history of surgery,stimulation scheme were analyzed by bivariate analysis and multivariable logistic regression.Results (1) Pregnancy rate:total of 141 pregnant cases and 185 nonpregnant cases treated by IVF were observed,pregnancy rate was 43.2％ (141/326).(2) Basic parameters:there was no statistical difference in age,BMI,basic FSH,AFC,CA125 and CA199 between clinical pregnancy group and non-pregnancy group (P ＞ 0.05).(3) Bivariate analysis:clinical pregnancy rate of 50.0％ (87/174) among patients with infertility year less than five years was significantly higher than 35.5％ (54/152) in patients with more than five years.Pregnancy rate of 56.1％ (46/82) in stage Ⅰ-Ⅱ was significantly higher than 42.5％ (79/186) in stage Ⅲ-Ⅳ.Pregnancy rate of 46.6％(125/268) with history of surgery was significantly higher than 27.6％ (16/58) with no history of surgery (P ＜ 0.05).Pregnancy rate of 48.2％ (79/164) in long-term scheme was higher than 38.3％ (62/162) in short-term scheme,but there was no significant difference (P =0.075).(4) Multivariable logistic regression:clinical pregnancy rate of infertility year with less than 5 years,stage Ⅰ-Ⅱ,history of surgery proved stage Ⅰ-Ⅱ and stage Ⅲ-Ⅳ was significantly higher compared with infertility year more than 5 years,stage Ⅲ-Ⅳ and no history of surgery respectively (adjusted OR and 95％ CI:2.003,1.263-3.175; 1.899,1.110-3.248; 3.769,1.802-7.887,P＜0.05).Conclusion Factors affecting clinical pregnancy rate of IVF in endometriosis related infertility were infertility year,stage and surgery.