The effects of ginseng, ginsenosides, coffee, and caffeine on 75% ethanol induced sleeping in mice were examined. Mice treated with ethanol lost their righting reflex within 30 min and this lasted for about 4 h. The onset time of lose of righting reflex (LR) in mice pre-treated with ginseng, ginsenosides, coffee or caffeine 10 min before ethanol was significantly delayed; whereas the duration of sleep was not affected by all treatments. Administration of these agents 10 min after ethanol was ineffective in counteracting the LR effect of ethanol. Coffee and caffeine produced central stimulation and increased locomotor activity. Ginseng and ginsenosides were found to enhance exercise endurance and reduced the plasma level of ethanol. Gastric emptying was slowed by ginseng, ginsenosides or ethanol administration. An additive effect was observed when the mice were pre-treated with ginseng or ginsenosides 10 min before ethanol administration. It is suggested that ginseng decreased plasma ethanol concentration by delaying gastric emptying and this may be partly due to the effect of the ginsenosides.