Abstract: OBJECTIVE To investigate the effect of two kinds of respiratory circuit disinfection methods of the anesthesia machine on the bacterial contamination in the respiratory circuit, so as to provide a reference for the choice of the respiratory circuit disinfection method of the anesthesia machine. METHODS A total of 46 closed-circuit anesthesia machines were used traditional disinfection and disinfector disinfection in the hospital from Jan. 2015 to Jul. 2015. The suction mouth side, exhalation side, sodium lime cans exports, and the entrance of the internal circuit system were sampled, and the bacteria were cultured and detected. RESULTS The pollution rates of anesthesia machine circuit system by traditional disinfection and disinfector disinfection before disinfection were 20.29% and 18.84%, no bacterium was detected after disinfection, and the pollution rates after 7 d were 2.90% and 2.17%, the differences at the different time points were significant (P<0.05). The pollution rates of exhalation side were the highest before and after 7d of disinfection, which were 20.29% and 2.90%. Totally 137 strains of bacteria were cultivated in the positive samples before disinfection, including 72 strains of gram-negative bacteria, 51 strains of gram-positive bacteria, and 14 strains of fungi, accounting for 52.55%, 37.23%, and 10.22%, respectively. Totally 13 strains of bacteria were cultured in positive samples after 7d of disinfection, including 7 (53.85%) strains of gram-negative bacteria, 5 (38.96%) strains of gram-positive bacteria, and 1 (7.69%) strain of fungus.CONCLUSION The use of traditional and disinfector disinfection of the respiratory circuit of the anesthesia machine can play a good disinfection effect, and reduce bacterial contamination in the respiratory circuit. Among the Contaminated bacteria, the proportion of gram-negative bacteria in the circuit before and after disinfection was higher than that of gram-positive bacteria.