Objectives : This study investigated whether the water extract of Spatholobi Caulis (SCE) has the ability to protect hepatocyte against oxidative stress induced by tert-butylhydroperoxide (tBHP) in vitro and in vivo. Methods : In vitro, HepG2 cells pre-treated with Spatholobi Caulis water extract (1, 3, 10, /ml) for 12h and further incubated with tBHP () for the next 12h. Cell viability was assessed by MTT assay. In vivo, rats were orally administrated with the aqueous extract of Spatholobi Caulis (SCE; 50, 100 mg/kg) for 4 days and then, injected with 1 mg/kg body weight to induce acute liver damage. Results : Treatment with SCE inhibited cell death induced by tBHP, as evidenced by alterations in the levels of the proteins associated with apoptosis:SCE prevented a decrease in , and cleavage of poly(ADP-ribose)polymerase and pro-caspase-3. Moreover, SCE inhibited the ability of tBHP to generate production, thereby restoring GSH content. Moreover, SCE treatments in rats effectively decreased liver injuries induced by a single dose of , as evidenced by decreases in hepatic degeneration and inflammation as well as plasma alanine aminotransferase and lactate dehydrogenase activities. Consistently, treatments of SCE also protected liver in rats stimulated by , as indicated by restoration GSH and prevention of MDA in the liver. Conclusions : SCE has the ability 1) to protect hepatocyte against oxidative stress induced by tBHP and 2) to prevent -inducible acute liver toxicity. Present findings may be informative not only in elucidating the pharmacological mechanism of Spatholobi Caulis, but in determining its potential application for oxidative cellular damage in the liver.