To evaluate the clinical efficacy and safety of high dosage levofloxacin injection in the treatment of hospitalacquired pneumonia(HAP) in intensive care unit (ICU).MethodsEightyfour  patients with HAP  in ICU from September ,2007 to December, 2008 were randomly divided into high dosage (HD group, n=50 ) and routine dosage levofloxacin injection treated group (control group, n=34), HD and control group both received  intravenous drip of levofloxacin 500mg, once per 16 hours and once per 24 hours respectively, therapeutic efficacy and adverse reactions in both groups were observed.ResultsThe total efficacy rate of HD and control group  was 88.00% and 76.47% respectively, there was  no significant difference between the two (χ2=1.94, P>0.05);  The effective time were (4.18±2.62)d and (5.64±2.72)d, the course of treatment  were (7.87±3.66)d and (9.64±3.52)d, bacterial eradication rate was 86.00% and 64.71%, respectively, there were  significant difference between  two groups (t=2.47, P<0.01; t=2.19, P<0.05; χ2=4.10, P<0.05); adverse reactions were observed in 12.00% and 8.82% of patients in  two groups respectively, there was  no statistical significance (χ2=0.01, P>0.05). ConclusionHigh dosage levofloxacin is effective and safe for HAP in patients in ICU,  and can save time for saving life, maybe widespread used.