To probe the organic constituents of over 2000-year-preserved Populus euphratica found in an ancient tomb, a chemical investigation was undertaken, which led to the isolation of a new compound, 2-(4′-hydroxy-3′ methoxyphenyl)-2-oxoacetamide (1), together with 12 known compounds (2–13) by column chromatography. Their structures were elucidated on the basis of spectroscopic evidence. It is the first time that compounds 2–13 were isolated from this plant.