Abstract:In order to understand the chemical constituents of Dendrobium sinense, ten compounds were isolated from whole herb by column chromatography. On the basis of spectral data, their structures were identified as chrysotoxine (1), 2',4'-dihydroxy chalcone (2), 2,5,7-trihydroxy-4-methoxy-9,10-dihydrophenanthrene (3), 4,7-dihydroxy-2,3-dimethoxy-9,10-dihydrophenanthrene (4), 2,5-dihydroxy-3,4-dimethoxy-9,10-dihydrophenanthrene (5), 2,7-dihydroxy-3,4,6-trimethoxy-9,10-dihydrophenanthrene (6), (E)-coniferyl aldehye (7), trans-p-hydroxylethyl cinnamate (8), p-hydroxyphenylpropionic methyl ester (9) and lasiodiplodin (10). All the compounds were obtained from this plant for the first time. Compounds 2, 6, 7 and 10 had a certain inhibitory activity on acetyl-cholinesterase.