To study the secondary metabolites of a marine-derived fungus Ascotricha sp. ZJ-M-5, several chromatographic methods including macroporous resin, silica gel, ODS and Sephadex LH-20 were used to isolate the compounds, and their structures were elucidated on the basis of physicochemical properties and spectroscopic methods. Ten compounds were obtained and identified as ascotrichic acid B (1), (3R)-6-hydroxymellein (2), beta-carboline (3), (22E, 24R)-ergosta-7, 22-diene-3beta, 5alpha, 6beta-triol (4), (22E, 24R)-ergosta-7, 22-diene-3beta, 5alpha, 6beta, 9alpha-tetraol (5), cyclo (Leu-Pro) (6), cyclo (Ile-Leu) (7), cyclo (Pro-Val) (8), cyclo (Pro-Gly) (9), and cyclo (Hpro-Ala) (10). Among them, compound 1 is a new 3, 4-seco-lanostane triterpenoid which has been isolated from the filamentous fungi for the first time, and compounds 2-10 are firstly isolated from Ascotricha genus.