In order to investigate the hepatoprotective constituents, Melonis Pedicellus was systematically extracted and fractionated with n-hexane, ethyl acetate, butanol and water Treatment of rats with ethyl acetate fraction reduced hepatic injuries induced by $alpha$-naphthylisothiocyanate or D-galactosamine, whereas the components in water fraction showed protective effect only against D-galactosamine-induced hepatitis in rats. Two cucurbitacins and three sterols were isolated from ethylacetate fraction and their chemical structures were identified as cucurbitacin B, isocucurbitacin B, $alpha$-spinasterol, stigmast-7-en-3-ol and stigmast-7-en-3-ol-0-$eta$-D-glucopyranoside. Cucurbitacin B at the dose of 1 mg/kg (p.o.) signifcantly increased in bile flow in rats with ANIT-induced cholestasis. Isocucurbitacin B at 5 mg/hg (p.o.) showed signilicant protective effects against ANIT-induced cholestasis. These results showed that cucurbitacin B and isocucurbitacin B from Melonis Pedicellus may have hepatoprotective effect in rats with experimental cholestasis.