By various chromatographic methods, three flavonoids, (2S)-naringenin (1), isorhamnetin 3-O-(2-O-${alpha}$-L-rhamnopyranosyl) ${eta}$-D-glucopyranoside (2), typhaneoside (3), and two sterol glycosides, ${eta}$-sitosterol-3-O-(6-octadecanoyl) ${eta}$-D-glucopyranoside (4) and ${eta}$-sitosterol-3-O-(6-octadeca-9Z,12Z-dienoyl) ${eta}$-D-glucopyranoside (5), were isolated from the pollen of Typha angustata. Their structures were determined on the basis of spectroscopic analyses. The flavonoids (1 - 3) were evaluated for their effects on the viability and proliferation of rat aortic smooth muscle cells. (2S)-naringenin (1) significantly inhibited cell proliferation in a dose-dependent manner without cytotoxic at concentrations of 30, and 50 ${mu}M$; it reduced the number of cells following PDGF-BB treatment to $1.83{pm}0.30{ imes}10^4$ and $2.20{pm}0.60{ imes}10^4$ cells/well, respectively. These findings suggest that (2S)-naringenin has antiproliferative effects on aortic smooth muscle cells.