Five new lanostane-type triterpenes, named fomefficinic acid A-E (1-5), were isolated from the dried sclerotium of Fomes officinalis, respectively. Their structures were established as 24-methylene-3-oxo-lanost-8-en-21-oic acid (1), 3a,15a-dihydroxy-24-methylene-lanosta-7,9(11)-dien-21-oic acid (2), 3a,15a-dihydroxy-24-methylene-lanost-8-en-21-oic acid (3), 15a-hydroxy-3-oxo-24-methylenelanost-8-en-21-oic acid (4), 15a-acetoxy-3-oxo-24-methylenelanosta-7,9(11)-dien-21-oic acid (5), by spectral analysis and chemical methods as well as comparison with known compounds.