As part of an ongoing search for immunomodulatory components aimed at the anti-complementary effect, ginsenosides isolated from processed ginseng were found to have inhibitory activity on complement activation through classical pathways. Activity-guided fractionation was used to isolate four ginsenosides, namely ginsenoside Rg₆, F₄, Rk₃, and Rh₄. Ginsenoside Rk₃ and Rh₄ had a 3 fold higher inhibition activity than rosmarinic acid which was used as a positive control while ginsenoside Rg₆ and F₄ showed only mild effects similar to that of the positive control. The results suggest that the activity of the corresponding ginsenosides may be increased by the glycosyl moiety at the C₆ position rather than the double bond conformation at C₂₀, and ginsenoside Rk₃ and Rh₄ could have a role in treating inflammatory diseases.