Objective To develop a new method for the rapid determination of lomefloxacin,gatifloxacin,ciprofloxacin and oflox-acin in plasm and urine by solid phase extraction(SPE)and capillary electrophoresis.Methods The capillary was fused silica capil-lary with id/od of 75/365 μm and effective/total length of 40/47 cm.The running buffer was 40 mmol/L borate buffer at pH 9.0. Separation voltage was 13 kV.Temperature was 20 ℃.Detection wave-length was set at 280 nm.The sample was analyzed after the pretreatment of SPE.Results The analysis of lomefloxacin,gatifloxacin,ciprofloxacin and ofloxacin was completed in 6 minutes with satisfied accuracy and precision.Good linearity was found within the range of 1-40 μg/mL,and the r was 0.998 7,0.997 6, 0.998 3 and 0.994 2 respectively.The recoveries of four quinolones in plasm and urine ranged from 80.1% to 107.6%,and the rel-ative standard deviations(RSD)ranged from 2.1% to 6.2%.Conclusion This method is fast,simple,precise and it might be feasi-ble for the determination of lomefloxacin,gatifloxacin,ciprofloxacin and ofloxacin in plasm and urine samples.