Objective To study the effect and mechanism of Erzhi Tiangui Granule（Granule for promoting the uterine functions） on infertility induced by luteal phase deficiency.Methods Sixty infertility patients owing to luteal phase deficiency were randomized into the tested group（treated with Erzhi Tiangui Granule） and the control group（treated with Liuwei Dihuang Granule）

30 in each.The improvement of TCM symptoms

the serum levels of estradiol（E2） and progestone（P）

the expression of leukemia inhibiting factor（LIF） of luteal metaphase before and after treatment

and the pregnancy rate were observed.Results After treatment

the tested group was significantly better than the control group in improving the TCM symptoms（P<0.05）;the serum level of progestone and LIF expression in the tested group were significantly higher than those in the control group（P<0.05）;the serum level of E2 in both groups was lower than that before treatment

but without significant difference（P>0.05）;the pregnancy rate in the tested group was higher than that in the control group（P<0.05）.Conclusion The mechanism of Erzhi Tiangui Granule treating infertility caused by luteal phase deficiency might be related to its function in increasing the LIF expression to improve the endometrial receptivity.