Experiment was performed to investigate the immunotoxicity of cadmium administered orally and the effect of ginseng petroleum ether fraction on it. Mice were given 3, 30, or 300 ppm cadmium as cadmium chloride orally in the drinking water and injection of ginseng petroleum ether fraction intraperitoneally for 4 weeks. Mice were sensitized and challenged with sheep red blood cells (S-RBC). Humoral immune response was evaluated by antibody production and Arthus reaction. Body weight gain, spleen weight, thymus weight, and liver weight were also measured. In the present study, cadmium generally suppressed the humoral immunity. There was decrease in the rate of body weight gain and liver weight to body weight by cadmium-administration. Ginseng petroleum ether fraction showed restoring effect, to some extent, on the decrease in PFC and in the rate of liver weight to body weight by cadmium-administration. But it more suppressed Arthus reaction.