The effect of species and concentration of electrolytic solution on the performance of anion exchange membrane (AEM) water electrolysis is experimentally examined. When potassium hydroxide (KOH) or potassium carbonate (K2CO3) solution is applied for the electrolytic solution, electrolysis is successful under mild alkaline conditions, whereas electrolysis with pure water is quite difficult due to the high resistance of the AEM. AEM electrolysis performance with K2CO3 solution is superior to that with KOH solution, even at similar pH of around 12. Hydrogen content in the anode gas compartment and relative humidity of produced hydrogen are also measured during the electrolysis. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.