In order to investigate the preclinical pharmacokinetics of cefuroxime lysine, a fast, sensitive and high throughput UPLC–ESI–MS/MS method has been developed and validated for the quantitative determination of cefuroxime in dog plasma. Cefuroxime and IS phenacetin were extracted from plasma samples by PPT or LLE procedure, and then separated on an ACQUITY UPLC™ BEH C18 column with an isocratic elution of acetonitrile–0.1% formic acid in 10mM ammonium acetate (40:60, v/v). MRM using the fragmentation transitions of m/z 442→364 and 180→110 in positive ESI mode was performed to quantify cefuroxime and IS, respectively. The calibration curves were linear over the concentration range of 2–400μg/ml for PPT and 0.01–5μg/ml for LLE. The LLOQ was 0.01μg/ml. The intra- and inter-day precisions in all samples were no more than 8.1%, while the accuracy was within ±6.2% of nominal values. The method was successfully applied to the evaluation of pharmacokinetic parameters of cefuroxime lysine in beagle dogs.