Korean ginseng has been thought and used the most very important medicinal herb among the oriental medicinal drugs for thounds of years Korean ginseng had many ingredients such as tripenoid saponins. Nitrogen compounds, polysaccharides, polyacetylenic compounds and lipid compounds. Korean ginseng has wide effects in the various systems of human such as nervous system. Vascular system. Digestive system. endocrine system, immune system. etc. Many researchess who were interested in the biological effects of Korean ginseng have concerned the tripenoid saponins among the components of ginseng and carried out to find the effects of ginseng using the various experimental system. From their results, it was unveiled many effects of Korean ginseng gractually in the experimental systems and shown that Korean ginseng has various effects in the biological system. But recent studies has been carried out to the difference ginseng components, besides ginseng saponin thought to have various effects in biological systems. Also the functional mechanism of ginseng in the biological system is limited but the basic research to elucidate the mysterious effects of ginseng has been preferred. In this review, we focus on biological effects of Korean ginseng. Especially physiological and biochemical aspects in biological systems.