Membrane electrode assemblies (MEA) prepared by direct spraying catalyst ink on water swollen membrane was presented for PEM water electrolysis. In the new fabrication process, hot water was inlet both as a swelling agent and heat source to improve the dimensional stability of Nafion 117 in spraying process. With such method, the membrane can also avoid shrinkage in catalyst ink drying process. The obtained MEA exhibited a larger voltammetric charge Q in anode and improved performance comparing with the conventional MEA, this may due to the surface area of membranes were expanded in catalyst spraying procedure. The influence of swelling temperature on the conductivity of Nafion 117 and the performance of water electrolyser was also investigated. The results indicate that the swelling-spraying method has the potential to fabricate the high quality MEA for PEM water electrolysis. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.