Abstract: Objective: To analyze the influencing factor of the in vitro fertilization and embryo transfer failure.Methods: The clinical data of 4886 patients were collected.The patients with assisted pregnancy success at the first time(1420 cases),324 success cycles and 365 failure cycles patients with assisted pregnancy success at two times and more than two times were divided into group A,B and C,respectively.The related factors of in vitro fertilization and embryo transfer failure were analyzed.Results: The age and infertile time in group A were significantly less and shorter than those in group B,respectively(P<0.01).The assisted reproductive technology(ART) results showed that long protocol in ovulation was often implemented in group A compared with group B,the mini-stimulation and antagonist protocol were often used in group B compared with group C,and the proportion of ICSI in group B was higher than that in group A and group C(P<0.01).The results of IVF also showed that the number of embryo transplantation in group B was more than that in group A,the total number of oocyte retrieval,fertilization rate,high quality embryo rate,number of available embryo,number of frozen embryo and implanting rate in group B were lower compared with group A(P<0.01),and the total number of oocyte retrieval,fertilization rate,cleavagerate rate,high quality embryo rate,number of available embryo,number of frozen embryo and implanting rate in group B were higher compared with group C(P<0.05 to P<0.01).Conclusions: The patients with older age,longer duration of infertility,less retrieved oocyte,less available embryo and poorer quality embryo are easy to lead to the in vitro fertilization and embryo transfer failure.