ObjectiveTo study the effectiveness of alkaline electrolyzed water (AEW) in the cleaning of medical instruments and its corrosive effect on metal. MethodsMedical instruments of solid smooth, solid with gear or tube were cleaned with AEW adding ultrasonic washing, cleaning efficacy were compared with conventional method, AEW without pulsing ultrasonic washing and control group,   corrosive effect of AEW on metal  immersed in AEW was tested. ResultsCleaning efficacy of solid smooth, solid with gear or tube instruments were significantly different among four groups（F=10.868, 14.268, 6.146，respectively,all P＜0.05）. For solid smooth instruments, cleaning with AEW adding ultrasonic and cleaning without ultrasonic had a better effect than  conventional cleaning (both P＜0.005）； For solid with gear instruments, AEW adding ultrasonic cleaning obviously had a better effect than conventional cleaning and AEW without ultrasonic cleaning(both P＜0.001）； For tube instruments, cleaning efficacy of three cleaning methods were not significantly different (all P>0.05）. AEW had no corrosive effect on stainless steel and copper. ConclusionThe cleaning efficacy of AEW on solid smooth, solid with gear instruments is superior to conventional cleaning method, and can  achieve better effectiveness  if  ultrasonic cleaning is added.