Two new pentacyclic triterpenoids, 2beta,3beta,16alpha-trihydroxyl-24alpha-al-olean-12-en-28-oic acid (1), 2beta,3beta-dihydroxyl-16-O-beta-D-glucopyranose-24alpha-al-olean-12-en-28-oic acid (2) and two known pentacyclic triterpenoids were isolated from the roots of Aster ageratoides var. pilosus. Their structures were elucidated by spectroscopic methods (IR, MS, 1H, 13C and 2D NMR). In addition, the anti-bacterial activity and anti-tumor activity of compound 2 were tested.