A simple, specific and sensitive HPLC method with UV detection was developed and validated for the determination of tectoridin in rat plasma for the first time. Chromatographic separation was performed on a Welchrom C(18) column (150 x 4.6 mm, i.d., 5 microm) at a flow rate of 1.0 mL min(-1), using a mixture of methanol-2% HAc aqueous solution (31:69, v/v) as the mobile phase with UV detection at 266 nm. The calibration curves for tectoridin were linear over the concentration range of 1.10-274.40 microg mL(-1) in rat plasma. The intra- and inter-day accuracies (RE) were within -3.23% and 4.11%. The intra- and inter-day precisions (RSD) were not more than 2.74 and 4.72%, respectively. The present method was successfully applied to the pharmacokinetic studies of tectoridin in rats after intravenous administration of three different doses.(c) 2009 John Wiley & Sons, Ltd.