ObjectiveTo study application effectiveness of different concentrations of chlorhexidine oral care solution in patients with orotracheal intubation. MethodsA total of 120 patients who were admitted to the general intensive care unit (ICU) of a hospital and undergoing mechanical ventilation via orotracheal intubation for >48 hours between January 2012  and  December 2013 were included in the study, they were divided randomly into three groups, 40 in each group. Trial group, control group I, and control group II were provided with 2%,0.2%, and 0.12% chlorhexidine oral care solution, respectively. Differences in halitosis, oral mucosal infection, onset time and incidence of ventilatorassociated pneumonia (VAP) among  three groups were observed and compared. ResultsThere were  significant difference in incidence of VAP  and earlyonset VAP between trial group and  control group I, trial group and  control group II, respectively(both P<0.05); incidence of  VAP in  control group II was higher than trial group（47.50% vs 20.00%，P=0.009）. Conclusion2% chlorhexidine oral rinsing and swabbing can effectively reduce incidence of VAP in patients with orotracheal intubation.