A new sterol, ergosta-8(14), 22-diene-3,5,6,7-tetraol(3beta, 5alpha, 6beta, 7alpha, 22E) (1), together with four known sterols ergosta-8(9), 22-diene-3,5,6,7-tetraol (3beta, 5alpha, 6beta, 7alpha, 22E) (2), 5alpha,8alpha-epidioxy-24(S)-methylcholesta-6,22-diene-3beta-ol (3), 5alpha,8alpha-epidioxy-24(S)-methylcholesta-6,9(11), 22-triene-3beta-ol (4), 3beta,5alpha,9alpha-trihydroxyergosta-7,22-diene-6-one (5) was isolated from marine fungus Pennicillium sp. Their structures were determined based on chemical analysis and spectral methods (IR, 1D and 2D NMR, HR-FAB-MS). Compounds 1-5 were evaluated for cytotoxicity against human liver cancer cell (Hep G), and most of them exhibited potent activity. Compound 1 display the highest potency with IC50 values 10.4 microg mL-1.