Abstract: RP-HPLC was applied to the determinations of fluoroquinolones including ofoxacin,norfloxacin,ciprofloxacin and enrofloxacin,in aquatic products.The sample was extracted by acetonitrile and acetic acid mixed solution,the extract obtained was purified with n-hexane.The MERK C18 column (4.6 mm× 150 mm,5 μm) was used as stationary phase,and a mixed solution of acetonitrile and tetrabutyl ammonium bromide (mixed in the a ratio of 6 to 94) was used as mobile phase.The eluate from column was used for HPLC analysis with fluorescence detector.External standard calibration was adopted in the determination.Linear relationships between the values of peak area and mass concentration of 4 fluoroquinolones were obtained.The values of recovery found by standard addition method were in the range of 93.0%-111.3%,and values of RSD′s (n=8) were less than 10%.