Objective: To study the pharmacokinetics of intravenous levofloxacin in patients with pulmonary infection.Methods: Levofloxacin concentration in serum were determinated by HPLC and the pharmaceutical parameters of levofloxacin were calculated.Results: The linear range was 0.8~6.4 mg/L(r=0.999 2).AUC0→12,t1/2 and ke of levofloxacin were(17.35±1.84) mg.h/L,(6.102±0.416 3)h 和(0.114 1±0.008 2) h-1,respectively.Conclusion: The serum concentration and AUC of levofloxacin in patients with pulmonary infection are smaller than that in healthy subjects.