To study the chemical constituents of the leaves of Aquilaria sinensis.The compounds were isolated and purified by the methods of solvent extraction and chromatographic technique, and their structures were identified on the basis of the analyses of spectral data.Eleven compounds were obtained and identified as beta-sitosterol (1), hexacosanic acid (2), cryptotanshinone (3), 2alpha-hydroxyursane (4), dihydrotanshinone I (5), tanshinone I (6), tanshinone II(A) (7), 2alpha-hydroxyursolic acid (8), p-hydroxybenzoic acid (9), hydroquinone (10), and daucosterol (11), respectively.All compounds except for compound 9 were isolated from the leaves of A. sinensis for the first time.