Objective:To investigate the chemical constituents in the BuOH extract of Asterias amurensis.Methods: The compounds were obtained by a combination of extraction and purification with suitable solvent and multiple column chromatographies; their structures were determined based on spectral analysis and physicochemical properties.The bioactivities of 5 compounds were tested.Results: Five compounds were isolated and identified,and they were amurensoside D(Ⅰ),tryptophan Ⅱ,and 3 sulfated sterols,including 3β-O-sulfated-6α,20β-diol-cholest-9(11)-en-23-one sodium salt(Ⅲ),3β-O-sulfated-6α-ol-cholesta-9(11),20(22)-dien-23-one sodium salt(Ⅳ),and 3β-O-sulfated-6α-ol-ergost-9(11)-en-23-one sodium salt(Ⅴ).Conclusion: TryptophanⅡ is obtained from this species for the first time; compoud Ⅲ and compound Ⅴ exhibit potent inhibitory activity against Pyricularia oryzae P-2b.