In this study, a UPLC-PDA method for simultaneous determination of catechin(1), isoorientin(2), orientin(3), quercetin-3-O-(2"-O-alpha-rhamnopyranosyl)-beta-glucarono-pyranoside(4), taxifoliol(5), luteolin(6), quercitrin(7) and kaempferol-3-O-beta-D-glucoside(8) in Polygonum orientale in Guizhou province was developed. Analysis was performed at 45 degrees C, on ACQUITY UPLC BEH C18 column (2.1 mm x 150 mm, 1.7 microm), eluted with a gradient program of acetonitrile-0.1% H3PO4 aqueous solution as the mobile phases. The flow rate was of 0.30 mL x min(-1), and the detection wavelength was 260 nm. The method validation proved that the linearity, instrument precision, repeatability, intermediate precision and accuracy accorded with the requirement for anassay. The established method had been used for determination above eight components in twenty lots of P. orientale in different places and harvest time in Guizhou province, and the results showed that the chemical composition was basically the same in herbs, but there were some difference in content of the tested components. the contents of the tested ingredients were relatively high and stable in the sample collected in August.