Endometrial cavity fluid（ECF）is a common phenomenon during the process of assisted reproductive techniques（ART）， which is associated with controlled ovarian stimulation（COS），hydrosalpinx，genital malformation，endometritis and so on.ECF affects the growth and development of embryos and the receptivity of endometrium，which results in the failure of embryos implantation.In this review，we summarize the etiology and treatment of ECF in order to know the effects of ECF on the outcome of ART during the period of embryos tansfer.