Objective To discuss the factor of levofloxacin led phlebitis.Methods 900 cases patients of intravenous drip levofloxacin were randomly divided into 9 groups(each of 100 cases),the levofloxacin 0.2mg+100ml liquid、levofloxacin 0.2mg+150ml liquid and levofloxacin 0.2mg+200ml liquid group and 51~60 drops/min、41~50 drops/min and 31~40 drips/min,35、30、20℃ group.Each groups and each factor were taken into concideration.Results The factor of levofloxacin 0.2mg+100ml liquid、51~60 drops/min and 20℃ were positively correlated with phlebitis.Conclusion The attention of levofloxacin intravenous drug concentration,dropping speed and temperature of the liquid to prevent phlebitis.