Abstract： Objective To evaluate the relationship between endometriosis fertility index (EFI) and pregnancies after laparoscopic surgery in endometriosis-associated infertility.Methods From Jan.2005 to Jan.2010,medical documents of 350 infertile patients due to endometriosis undergoing laparoscopic surgery were studied retrospectively.Pregnancy outcomes were followed up by telephone.EFI was calculated by history factors,least function score and some aspects of the revised American Fertility Society (r-AFS) endometriosis stage.The cumulative pregnancy rate was calculated and compared by Kaplan-Meier survival analysis.Results Within 3 years after surgery,the cumulative pregnancy rates among patients with EFI score 8,9,10 were 62.5％,69.8％ and 81.1％,respectively.There was no significant difference in pregnancy rates among those three groups of patients ( P =0.24 ).The cumulative pregnancy rates among patients with EFI score 5,6,7 were 49.8％,43.9％ and 41.6％,respectively,which did not reach statistical difference ( P =0.83 ).The cumulative pregnancy rates of EFI score 8 - 10 was significantly higher than that of EFI score 5 -7 (71.8％ vs.44.4％,P =0.000).The patients with EFI score 0 -4 was quite small with only 33 cases,among which 15 cases were pregnant.Conclusions There is relationship between EFI and pregnancy in patients with endometriosis-associated infertility.EFI is meaningful to guide post surgical treatment.