Objective : The immune system is a complex of systems, all of which work together to clear infection from the body. In Korea, red ginsenghas been one of the herbs most widely used to enhance the immune system for thousand of years. More recently, red ginseng has been reported to have many positive effects on the immune system. The purpose of this study was evaluate the effects of Korean red ginseng and Chinese red ginseng on IgG, IgM, and IgA, using immunoglobulin productivity assay. Methods : Male SD rats were separated into 3 groups. We administered Korean red ginseng (KRG) to one group and Chinese red ginseng (CRG) to another, with normal saline for the Control group consecutively and orally for 3 months. The dose of red ginseng was 500mg per day, as a powder with soluble water. Immunoglobulin levels from spleen cell were estimated by ELISA kit. Results : In immunoglobulin productivity assay (cell), the IgG level of the KRG group significantly increased but there was no significant difference in the IgG of the CRG group. The IgM level of the KRG group significantly increased stimulated with PWM. When it was unstimulated, the level of IgM in KRG and CRG increased together. The IgA level of the KRG group significantly increased when it was stimulated with PWM and unstimulated. Conclusion : According to the above results, oral administration of red ginseng for 3 months is considered useful for immunomodulatory effect, and Korean red ginseng may be superior to Chinese red ginseng in that effect.