Bioassay-guided investigation of the stem bark of Hopea chinensis led to the isolation of two new polyphenols, hopeachinols C(1) and D(2), together with ten known compounds (3-12). Compounds 1 and 2 were determined by extensive analysis of spectroscopic data and computational methods. All of these phytochemicals were tested for acetylcholinesterase inhibitory activity, and five resveratrol-derived compounds (1 and 7-10) exhibited significant activity with their IC(5)(0) values ranging from 4.81 to 11.71 microM.