Abstract: The bean sprout sample blended with homogenizer was extracted ultrasonically with phosphate buffer. The extract was purified with HLB solid phase extraction column, and then eluted with methanol. UHPLC-MS/MS was applied to the determination of enrofloxacin and ciprofloxacin. Agilent Eclipse Plus C₁₈ RRHD chromatographic column was used as stationary phase, and the mixture of methanol and 0.1% (φ) formic acid-2 mmol·L^-1 ammonium acetate solution mixed in different ratios was used as mobile phase in gradient elution. ESI⁺ and multi-reactions monitor mode were adopted in MS/MS. Isotope was used as internal standard. Linearity ranges of enrofloxacin and ciprofloxacin were both found between 0.5 μg·L^-1 and 50.0 μg·L^-1, with detection limit (3S/N) of 0.025 μg·kg^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 89.2%-101%, with RSDs (n=6) of determined values in the range of 3.3%-9.2%.