To evaluate the disinfectant efficacy of  ethanol on transparent PVC endotracheal tube , as well as  the best replacement time. MethodsPhase I: 58 patients with transparent PVC endotracheal tube  between April and  July 2011 were  selected , the concentration and bacterial count of ethanol used for immersion disinfection of transparent PVC endotracheal tube were detected at different time point (upon opening of the new ethanol and 12, 24, 48 and 72 h after opening ), ethanol was used continuously for 72 h . Phase II: 46 patients with transparent PVC endotracheal tube between July and  November 2011 were  selected and divided into experimental group (new process: immersion tank and ethanol were changed every 48 h) and control group (former process: immersion tank and ethanol were changed every 24 h), the frequency of change, manpower, cost and incidence of infection within one month between two groups were compared .ResultsThe difference between ethanol upon opening and 12, 24 as well 48 h after opening  were not statistically significant (all P>0.05);72 h after opening, ethanol concentration was significantly lower than the newly opened (［71.82±0.77］%vs ［72.98±0.83］%,t=17.60,P<0.05). Disinfection efficacy of ethanol at different time points all met the required standards. Cost of experimental group was significantly lower than the control group (CNY［56.70±9.30］ vs CNY［178.20±4.70］),  and manpower was also significantly lower than the control group (［37.20±5.80］ persontime/month vs ［120.30±6.70］ persontime/month,all P<0.05); Incidence of infection was not statistically significant between two groups(13.04% vs 17.39%,t=0.17,P>0.05). ConclusionEthanol immersion disinfection is a effective, low cost, easy operation and safe disinfection method, ethanol can be used continuously for 48 hours before changed  if ethanol tank is sealed well and with low opening frequency.