Abstract: AIM: To investigate the chemical constituents in the fruits of Aquilaria sinensis. METHODS: The chemical constituents were isolated by column chromatography on silica gel and Sephadex LH-20, and their structures were elucidated on the basis of spectroscopic analysis. RESULTS: Five compounds were isolated and identified as hexanorcucurbitacin I (1), cucurbitacin I (2), cucurbitacin D (3), isocucurbitacin D (4), and neocucurbitacin B (5). CONCLUSION: Compounds 1-5 were reported from Aquilaria genus for the first time. Compounds 1, 2, 4, and 5 showed cytotoxic activities against K562, SGC-7901 and SMMC-7721.