Objective：To explore the role of growth factor receptor bound 7（GRB7） during embryo implantation through detecting its expression pattern in the mouse endometrium. Methods：Expression of GRB7 mRNA and protein in the non-pregnant and pregnant mouse endometrium from d1 to d7 was examined by qRT-PCR，immunohistochemistry and Western blot. GRB7 antisense oligo-nu－cleotide was injected at 8 pm on pregnancy d3 and embryo implantation number on pregnancy d7 was examined. Results：GRB7 mR－NA expressed in uterine endometrium of the non-pregnant and pregnant mouse from d1 to d7 and reached the highest level on preg－nant d5 based on the results of qRT-PCR. Immunohistochemistry and Western blot showed that the expression pattern of GRB7 in mouse endometrium was the same with that detected by qRT-PCR. Moreover，from pregnant d1 to d4，GRB7 was mainly expressed in epithelium and glandular cells and was lowly expressed in stromal cells；on d5 and d6，GRB7 was more intense in epithelium and glandular cells and was obviously expressed in stromal cells，especially on d5. On d6，GRB7 was expressed strongly in primary decid－ual zones at implantation sites and stromal cells at inter-implantation sites，respectively. After horn injecting GRB7 antisense oligonu－cleotides，the number of embryo implantation was obviously decreased when compared with that in control group. Conclusions：Differ－ential expression of GRB7 in pregnant mouse endometrium suggests that GRB7 may involve in the process of embryo implantation.