A bioassay-guided fractionation and chemical investigation of the trunk of Berberis koreana led to the isolation and identification of three new triterpenoids, 2 α,3 α,19 α-trihydroxy-urs-12-en-24-formyl-28-oic acid (1), 2 α,3 β,21 α-trihydroxy-urs-12-en-28-oic acid ( 2), and 3 β-acetyloxy-1-oxo-olean-12-en-28-oic acid (3), along with seven known triterpenoids (4-10). The structures of these ne...