This work described a sensitive method for determination of metoprolol in rabbit plasma. The method involved purification by ultrafiltration, derivatization with fluorescein isothiocyanate, determination by capillary electrophoresis (CE) coupled with laser-induced fluorescence (LIF) detector. Other components in plasma including a variety of amino acids and proteins did not interfere with the determination of metoprolol in experimental condition. The assay had a wide range (2.0-500 ng/mL) of linearity and a detection limit of 0.8 ng/mL. The intra-and inter-day precisions were satisfactory with relative standard deviation (RSD) less than 10.0% and accuracy within 10.0%. This method was successfully applied to pharmacokinetic study of metoprolol in rabbit blood. (c) 2010 Yu Yun Chen. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.