Objective:To investigate the effect of PCNA in the mouse uterus during embryo implantation.Methods:Real-time fluorescence quantitative PCR(FQ-PCR) was used to detect the PCNA mRNA of the mouse of unpregnancy

pregnancy at d2

d3

d4

d5

d6 and d7.PCNA monoclonal antibody was injected in horn of uterus at pregnant d3.Results: The expression of PCNA mRNA showed gradual hoist trend as days passed

and at pregnant d4

d5 it reached the maximum

at pregnant d6

d7 it showed gradual descent trend.The number of blastocysts in horn of uterus which was injected PCNA monoclonal antibody was smaller than in that of injected with Saline.Conclusion: PCNA is persistently expressed in mouse endometrium during the early pregnancy and maybe participates in the regulation process of mouse blastodysts implantation.