Four new sterols, 5α,6α-epoxy-(22E,24R)-ergosta-8(14),22-diene-3β,7β-diol (1), (22E,24R)-ergosta-8,22-diene-3β,5α,6β,7α-tetrol (2), (22E,24R)-ergosta-7,9(11),22-triene-3β,5α,6β-triol (3) and 3β,5α,6β-trihydroxy-(22E,24R)-ergost-22-en-7-one (4), have been isolated from the fruit bodies of Grifola frondosa (FR.) S. F. GRAY (Polyporaceae) together with fourteen known ones (5-18), of which two (5 and 6) are reported for the first time from a natural source. The structures of these compounds were elucidated on the basis of spectral data.