Purpose To investigate the effect of Ag-1031 on apoptosis of gastric cancer AGS cells and the PI3K/AKT/mTOR signaling pathway. Methods Gastric cancer cells were treated with different doses of Ag-1031. Cell viability was determined with MTT assay. Apoptosis was analyzed with Hoechst 33342 staining and Annexin V-FITC/PI double staining. The protein expression levels of p-PI3K, p-AKT, p-mTOR, PI3K, AKT and mTOR were assayed with western blotting method. Results Different doses of Ag-1031 significantly inhibited the proliferation of AGS cells. Moreover, Ag-1031 induced apoptosis,in gastric cancer cells. In addition, Ag-1031 significantly and dose-dependently inhibited the protein expressions of p-PI3K, p-AKT and p-mTOR. However, it had no effect on the protein expressions of PI3K, AKT and mTOR. Conclusion In this study, it was found for the first time that Ag-1031 exerts an anti-tumor effect by induction apoptosis in gastric cancer AGS cells, through a mechanism related to inhibition of the activation of the PI3K/AKT/mTOR signaling pathway.