Objective:To observe whether the in-flow anesthetic gas absorber can reduce the recovery time after stopping inhalation of enflurane or isoflurane. Methods: In fixed tidal volume, minute volume and fresh gas flow, the recovery time of isoflurane or enflurane anesthesia with or without in-flow anesthetic gas absorber were compared after closing the vaporizer.Results: With in-flow anesthetic gas absorber, the time for anesthetic gas concentration in circle to reduce the MAC to 0.3was 3.3±0.5 min for isoflurane, which was significntly shorter than that without absorber (20±0.3min) ( P＜0.01 ) and the time for enflurane was 3.5±0.5min and 25±0.1min respectively. Conclusion:Anesthetic gas absorber can reduce the recovery time of either enflurane or isoflurane inhalational anesthesia significantly.