Abstract: To evaluate the receptivity of the endometrium comprehensively by qualitative assessment include endometrial thickness， echo pattern， volume， exercise status， blood circulation and other factors， and quantitative assessment include endometrial blood flow parameters by colour Doppler， to the purpuse of comprehensive evaluating the receptivity of the endometrium. The aim of this report is to summarize the value of colour Doppler in in vitro fertilization and embryo transfer（IVF-ET）， and to find a safe， non-invasive and accurate way, which would guide embryo transfer， predict and improve IVF?-ET pregnancy rate and decreasing multiple pregnancy rate.

Key words: Ultrasonography, Doppler, color, Fertilization, in vitro, Embryo transfer, Endometrium, Pregnancy rate