Background Surgery is the only treatment option for operable gastric cancer. The CLASSIC and ACTS-GC studies showed that the 5-year overall survival (OS) of patients with stage III gastric cancer undergoing D2 gastrectomy is still very low. Whether adjuvant nanoparticle albumin-bound paclitaxel (nab-paclitaxel) combined chemotherapy is more effective than the XELOX standard adjuvant chemotherapy in patients with stage III gastric cancer has not been confirmed. Methods This is a multicenter, open-label, phase III clinical study. In this trial, 616 patients with locally advanced stage III gastric cancer that underwent curative D2 radical surgery and achieved R0 are planned to be included. Patients will be randomized 1:1 to nab-paclitaxel combined with S-1 (AS) vs. oxaliplatin combined with capecitabine (XELOX). XELOX group: Patients assigned to the XELOX group received eight 3-week cycles of oral capecitabine (1000 mg/m(2)) twice daily on days 1-14 of each cycle plus intravenous oxaliplatin 130 mg/m(2) on day 1 of each cycle. AS group: AS group received eight 3-week cycles of oral S-1 (80-120 mg) (< 1.25 m(2), 40 mg; 1.25 to < 1.5 m(2), 50 mg; and > 1.5 m(2), 60 mg) twice daily on days 1-14 plus intravenous nab-paclitaxel 120 mg/m(2) on days 1 and 8 of each cycle. The primary endpoint was the 3-year disease-free survival (3-year-DFS) defined as the time from randomisation to the time of recurrence of the original gastric cancer, development of a new gastric cancer, or death from any cause. The secondary endpoints were the overall survival, (defined as the time from the date of randomisation to date of death from any cause) and safety (any adverse event). Discussion Compared with previous studies, this study includes nab-paclitaxel based on S-1 adjuvant chemotherapy, which is expected to achieve better efficacy and lower toxicity than the standard treatment. This study is the first clinical study to evaluate the safety and efficacy of nab-paclitaxel combined with S-1 in patients with stage III gastric cancer after D2 radical resection.