The aim of this study was to evaluate prospectively the impact of the red ginseng extract on circulating interleukin (IL) 2 and 10 in advanced gastric cancer during chemotherapy after operative treatment. Analysis of circulating IL-2 and 10 was performed in 50 patients with advanced gastric adenocarcinoma who underwent a curative surgery or with an unresectable gastric adenocarcinoma by using ELISA and monoclonal antibodies at preoperative day 1, postoperative months 1, and 3. Twenty-five patients as the control group, twenty-six patients as the non-ginseng (NG) group, and twenty-four patients as the ginseng (G) group were eligible in this study. All plasma IL-2 of the NG and G groups was significantly lower an that of the control group on preoperative 1 day. These values of the G group were more increase than these of the NG group during the postoperative chemotherapy. The mean value of serum IL-10 of the control group (0.608pg/ml) was significantly lower than that of the advanced gastric cancer patients including the NG (12.015 pg/ml) and G group (9.409 pg/ml) (p＜0.001). These values of the G group were reduced progressively during the postoperative chemotherapy. The mesh value of the G group were only close to that of the control group on postoperative months 3 (p=0.003). The number of patients who were enrolled in this study was relatively small to fully evaluate the immunologic effects of the red ginseng extract on circulating IL-2 and 10. Despite this limitation, these results suggest that the post-operative intake of the red ginseng extract have potential to improve earlier anti-cancer immunity with recovering IL-2 and reducing IL-10 from the depressed IL-2 and elevated IL-10 by gastric cancer during the postoperative chemotherapy. This study will be based on the future study to evaluate the anti-immunity of the red ginseng extract.