To study the chemical constituents of leaves of Acer saccharum.The leaves of Acer saccharum were extracted by ethanol. The concentrated material was partitioned by petroleum ether, ethyl acetate, and n-butanol. After extracted by ethyl acetate, the extract was isolated and purified by silica gel column chromatography and recrystallization. The compound structures were identified on the basis of spectral data and chemical methods.Seven compounds were isolated from the leaves of Acer saccharum. Their compound structures were identified as 3-keton-ursane,3beta-hydroxy-12-olean-12-en and 5-en-7-hydroxy-sitosterol.All the three compounds identified are isolated from this genus for the first time.