Objective To evaluate the effect of Axl over expression on subcutaneous tumorigenesis of gastriccancer cell lines in nude mice. Methods The relationship between Axl and gastric cancer was analyzed by immunohistochemical staining. Axl-overexpressing gastric cancer cells were constructed through lentivirus transfection. The nude mouse model was established by subcutaneous injection of gastric cancer cells, and tumor sizes were evaluated byimaging of live animals. Results Immunohistochemical result revealed significantly higher Axl expression in gastric cancertissues compared with adjacent tissues. Axl expression in the Axl-overexpression gastric cancer cell line was increased by2. 4-fold. Live imaging of model mice revealed that after subcutaneous injection of cell lines for 2 weeks, tumors constructedwith the Axl-overexpression cell line were significantly larger than that of the control group, and this difference was moresignificant after 4 weeks ( P < 0. 01). Finally, the volume and weight of subcutaneous tumors formed by gastric cancer cells with high Axl expression were significantly increased compared with the control group. Conclusions Axl overexpression can enhance the subcutaneous tumorigenicity of SGC-7901 cells.