Abstract: A new pentacyclic triterpenoid compound (1) and three known compounds (2-4) were isolated and purified from the biogas slurry by various liquid chromatographys. The new compound was named as 24-norolean-4,12-diene-3,22-dione,the other 3 compounds were identified as 6-hydroxy-3,4-dihydroquinolines-2-ketone (2), (E)-3-(2-hydroxy benzene) acrylamide (3) and phenylacetate (4),respectively.They were isolated from the biogas slurry for the first time.

Key words: biogas slurry, chemical constituents, 24-norolean-4,12-diene-3,22-dione, phenylacetate