Gastric cancer (GC) is the second most common cancer in China. The ToGA study showed that trastuzumab in combination with fluoropyrimidine plus cisplatin prolonged overall survival (OS) in patients with human epidermal growth factor receptor 2 (HER2)-positive advanced GC (AGC). However, some patients may not be able to receive this regimen. We conducted a clinical study to evaluate the efficacy and safety of trastuzumab in combination with docetaxel+capecitabine (DX) in patients with HER2-positive AGC. This phase II, multi-center, open-label, single arm study enrolled patients with HER2-positive AGC who had not received prior treatment for metastatic disease. Patients were treated with a regimen of trastuzumab (8 mg/kg loading dose followed by 6 mg/kg, day 1), capecitabine (1000 mg/m2 twice daily, days 1-14) and docetaxel (60 mg/m2, day 1 for 6 cycles) every 3 weeks. The primary endpoint was progression-free survival (PFS) and the secondary endpoints were objective response rate (ORR), OS and safety profiles. Sixty-seven patients with AGC were enrolled from 14 centers. 64 were included in the full analysis set (FAS). The median PFS was 8.1 months (95% confidence interval [CI]: 5.6-12.8) and the median OS was 20.9 months (95% CI: 15.1-33.0). Response was evaluated in 59 patients. The ORR was 67.8%. The most common adverse events of Grade ≥3 were neutropenia, leukopenia, hand-foot syndrome, febrile neutropenia and anemia. We concluded that combination treatment with trastuzumab and DX was well-tolerated and highly effective in patients with HER2-positive AGC, and may offer an alternative to current treatments. AJCR Copyright © 2020.