An HPLC method was developed for simultaneous quantitation of rosmarinic acid, oridonin and chrysoplenetin in the aerial parts of Isodon rubescens. Samples were analyzed on an Ultimate C18 column (4.6 mm x 250 mm, 5 microm) with methanol and water containing 0.1% formic acid as mobile phases in a linear gradient mode. The flow rate was 1.0 mL x min(-1) and the temperature was set at 30 degrees C. The PDA detector wavelengths were set at 338 nm for rosmarinic and chrysoplenetin and at 242 nm for oridonin. The linear ranges were 0.222-2.78, 0.227-2.84 and 0.005-0.071 microg for rosmarinic acid, oridonin and chrysoplenetin, respectively. The average recoveries of the three constituents were 102.9% (RSD 1.9%), 99.6% (RSD 1.1%) and 102.5% (RSD 0.94%), respectively. This method was proved to be accurate and repeatable, and can be used for quality control of the aerial parts of I. rubescens.