By various chromatographic methods, three flavonoids, (2S)-naringenin (1), isorhamnetin 3-O-(2-O-α-L-rhamnopyranosyl) β-D-glucopyranoside (2), typhaneoside (3), and two sterol glycosides, β-sitosterol-3-O-(6-octadecanoyl) β-D-glucopyranoside (4) and β-sitosterol-3-O-(6-octadeca-9Z,12Z-dienoyl) β-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 μM; it reduced the number of cells following PDGF-BB treatment to 1.83 ± 0.30 × 10(4) and 2.20 ± 0.60 × 10(4) cells/well, respectively. These findings suggest that (2S)-naringenin has antiproliferative effects on aortic smooth muscle cells.