Abstract: Objective To study the effects of Cdx2 overexpression on growth and metastasis of transplanted tumor of human gastric cancer in nude mice. Methods The recombined eukaryotic expression vector pCMV-Cdx2-HA or empty vector pCMV-HA was transfected into gastric cancer MGC-803 cells individually by Lipofectamine，which was named as MGC-803/Cdx2 cells or MGC-803/EV cells.BALB/C nude mice were inoculated subcutaneously with MGC-803/Cdx2 cells or MGC-803/EV cells and then the subcutaneous tumor was transplanted into stomach.The nude mice transplanted with MGC-803/Cdx2 tumor were named as the experimental group while the nude mice transplanted with MGC-803/EV tumor were named as the control group.After mice were executed，the volume of transplanted tumor was measured and tumor metastasis was observed.The expression of Cdx2 in tumor tissue was detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Results The volume of transplanted tumor in the experimental group was (13.42±2.34) mm3，which was lower than that in the control group (P<0.05).Meanwhile，the rate of tumor formation in the experimental group (73.3%) was lower than that in the control group (86.7%).The situation of tumor metastasis was not difference between the control group and the experimental group (P>0.05).Compared with the control group，both Cdx2 mRNA and protein were upregulated in the experimental group (P<0.05). Conclusion Cdx2 overexpression inhibites growth of transplanted tumor of human gastric cancer in nude mice，but it has no effect on tumor metastasis.