The stems of Acer tegmentosum Max were extracted with MeOH and then partitioned with $CH_2Cl_2$, n-BuOH, and $H_2O$, successively. Three compounds were isolated from the $CH_2Cl_2$ fraction through repeated column chromatographic separation. Their chemical structures were elucidated as ${eta}$-sitosterol, ${eta}$-sitosterol-3-O-${eta}$-D-glucoside, and epifriedelinol by comparison of spectral data with those in references. These three compounds were firstly isolated from this plant.