 Chemotherapy is indispensable for gastric cancer. First-line chemotherapy consists of multi-drug regimens including oral five-foo agents such as S1 slash salota and platinum preparations. In Eastern countries, postoperative adjuvant chemotherapy has been successful, including S1, dostaxyl slash S1, ds, and salota slash oxalipitin, xylox regimens. This article was authored by Keishi Yamashita, Keho Soda, Masahiro Nihara, and others.