A new phenolic compound, 4-dehydrochebulic acid-1,6-dimethyl ester (2) was isolated from the leaves of Sapium insigne (Royle) Benth. ex Hook. fil. (Euphorbiaceae) along with three known compounds gallic acid (1), brevifolin carboxylic acid (3) and fraxin (4). Structures of those compounds were elucidated on the basis of spectroscopic data.