In an attempt to explore the effect of Ginseng on the permeability of the biological membrane to cations we have investigated the effect of Ginseng-alcohol extract on the transport of Na⁺ human red blood cell preprations. The Na⁺ influx was measured in intact red cells using ²²Na as a tracer and the efflux in reseated red cells using ²⁴Na as a tracer. 1. The influx of Na⁺ was not apparently changed by the Ginseng-alcohol extract of 20mg% in the incubation medium. 2. Similarly, 20mg% Ginseng-alcohol extract in the cellular space did not alter the efflux of Na⁺ from the cell. However, 50mg% of Ginseng-alcohol extract in the cell resulted in a significant increase in the Na⁺ efflux and this effect was magnified when the cell was suspended in the medium containing the Ginseng-alcohol extract in a concentration of 20mg %. The results suggest that Ginseng-alcohol extract over 50mg% increase permeability of red blood cell membrane to Na⁺ by altering the membrane integrity.