采用微量平板稀释法测定肝胆外科病人口服左氟沙星后的血清和胆汁的杀菌效价。结果表明，左氟沙星对链球菌、变形杆菌、肺炎克雷伯氏菌杀菌活性最强，血清杀菌效价为１８～１１６，胆汁杀菌效价为１３２～＞１２５６，且杀菌作用能维持在８ｈ以上；对大肠埃希氏菌、金葡球菌杀菌作用较强，胆汁杀菌效价为１８～１１６，其杀菌作用也能维持８ｈ以上，但其血清杀菌效价为１４，对铜绿假单胞单胞菌的杀菌作用较低，８ｈ后无作用 Bactericidal titer of serum and bile after oral levofloxacin in patients with hepatobiliary surgery by microtiter plate dilution method. The results showed that levofloxacin had the strongest bactericidal activity against Streptococcus, Proteus and Klebsiella pneumoniae, the serum bactericidal titer was 18 ~ 116, the bile bactericidal titer was 132 ~> 1256, and the bactericidal effect was maintained at 8h or more; against Escherichia coli, Staphylococcus aureus strong bactericidal effect, bile bactericidal titer of 18 to 116, the bactericidal effect can be maintained for more than 8h, but the serum bactericidal titer of 14, Pseudomonas aeruginosa Sterilization of monocytogenes is low, no effect after 8h