Abstract: Objective:To evaluate the efficacy and adverse reaction caused by Capecitabine compared with S- 1 as maintenance treat -ments for patients with advanced gastric cancer (AGC) after first-line induction chemotherapy. Methods:A total of 130 AGC patients who did not suffer disease progression after first-line chemotherapies, including XELOX (four to six cycles), SOX (four to six cycles), and mFOLFOX 6 regimen (six to eight cycles), were randomized into three groups. The Capecitabine group (Cap) received maintenance che -motherapy with Capecitabine (1 000 mg/m2 twice daily for 14days,21days/cycle), while the S- 1 group (S1) received S-1 (40, 50, or 60 mg according to the body surface area and orally administered twice a day for14days,21days/cycle). The control group was consid-ered as the observation group. Patients with maintenance treatments received drugs until disease progression or observation of intol-erant toxicity. Results:A total of 44, 33, and 53patients received XELOX, SOX, and mFOLFOX6 regimens, respectively. The overall DCR was 63. 1%. Among the 82patients, 35, 28, and 19belonged to the Cap, S1, and observation groups, respectively. The comparison be -tween the efficacy of treatments in the Cap and S1 groups did not show statistically significant differences( P=0. 678 ). The median time of progression was 8. 5 months in the Cap group and9. 0 months in the S1 group ( P>0. 05). Both groups showed better responses than the observation group, which demonstrated a median progression of 6. 0 months (P<0. 001 ). The median overall survivals were 14. 5, 15. 0, and 14. 0 months in the Cap, S-1, and observation groups, respectively ( P=0. 188 ). The most common adverse effects observed among the patients with maintenance treatments included myelo-suppression, gastrointestinal reaction, fatigue, hand-foot syndrome, and stomatitis. No death occurred in relation to the therapy. Conclusion: The effectiveness of Capecitabine and S- 1 as maintenance chemotherapies in AGC patients after the first-line induction chemotherapy are similar, and both can prolong the time of disease pro -gression with low toxicity.