Objectives: This study was conducted towards developing guidelines of herbal medicine treatment for gastric cancer. Methods: We performed a systematic review and meta-analysis designed to investigate the efficacy of herbal medicine treatment for gastric cancer on four cancer questions; survival rate, metastasis, immune function, and quality of life. Based on the findings, we utilized a two-round delphi process with panel of 22 experts for their level of agreement. Results: Combined therapy group, herbal medicine treated with chemotherapy, was significantly higher in the 1-year survival rate (RR=1.27, 95% CI: 1.14 to 1.40, P=0.005, $I^2=71%$) and 3-years survival rate (RR=1.41, 95% CI: 1.16 to 1.71, P=0.91, $I^2=0%$) than chemotherapy group. The suppression of metastasis was higher in the combined therapy group (RR=0.62, 95% CI: 0.45 to 0.84, P=0.09, $I^2=54%$). The immunology function was higher in the combined therapy group compared with the chemotherapy group (MD=16.43, 95% CI: 13.25 to 29.61, P<0.001, $I^2=99%$). The quality of life score was higher in the combined therapy group compared with the chemotherapy group (RR=1.55, 95% CI: 1.21 to 2.00, P<0.66, $I^2=0%$). Conclusions: Among the Randomized controlled trials (RCT) included, the levels of survival rates, suppression of metastasis, immune function, and quality of life of the group treated with chemotherapy were lower compared to those treated with herbal medicine in addition to chemotherapy.