Ginsenoside Rd (GS-Rd), isolated from the Chinese traditional herbal medicine Panax ginseng, is used for the treatment of cardiovascular diseases, inflammation, different body pains, and trauma. Caspase-3 and Caspase-9 belong to cysteine aspartic acid specific protease (Caspase) family that plays an important role in apoptosis progression of cancers. In the present study, we investigated the anti-tumor effect of GS-Rd by MTT assay, colony formation assessment, flow cytometry, and Western blotting. Our results revealed that ginsenoside Rd significantly inhibits human gastric cancer (GC) growth and cell proliferation. Flow cytometer analysis showed that the GS-Rd could significantly induce apoptosis and arrest the G0/G1 phase in GC cells. Further, GS-Rd was found to increase the ratio of Bax/Bcl-2 and the expression of Caspase-3 and Caspase-9, respectively, and to decrease the expression of Cyclin D1. Taken together, our study suggests that GS-Rd significantly inhibits GC cell proliferation, induces cell apoptosis through increase the expression of Caspase-3, Caspase-9, and the ratio of Bax/Bcl-2. GS-Rd also induces cell cycle arrest at G0/G1 phase by down-regulation Cyclin D1. Thus, GS-Rd could serve as a lead to develop novel therapeutic agents to against human gastric cancer.