Artesunate ( Art ) is one of the derivatives of Qinghaosu ( Arte-misinin ), an effective and nontoxic new drug from the traditional Chinese medicine Qinghao ( Artemisia annua L. ).We observed a striking protection of Art against acute liver inju-ries induced by Acetaminophen(AAP)and CC14 in mice. The elevated serum transminase levels and liver lesions were reduced by Art given 100mg/kg or 200mg/kg ip to mice. Art also inhibited AAP-induced decrease of liver glycogen and reduced mortality in AAP-treated mice. In addition, Art markedly decreased the duration of the hypnosis of sodium pen tobarbital in mice, suggesting a stimulatory effect of Art on hepatic-metabolizing enzymes.