In this study, in-plane gas permeability and through-plane resistivity of gas diffusion layer (GDL) made by different microporous layers (MPLs) were characterized by a new combined measurement setup under different compression ratios. Applied MPL ink-homogenizing techniques were pulse sonication, continuous sonication, bath ultrasonic and mechanical stirring. Results showed that 20% GDL compression produced optimized in-plane gas permeability and through plane resistivity, which is suitable for application in proton exchange membrane fuel cell (PEMFC). However, bath ultrasonic technique is more desirable technique for MPL ink homogenization in term of obtained gas permeability and total resistivity values; 0.45 (x10(-12) m(2)) and 2.63 (m Omega) cm(2)) respectively. Morphological investigation was also presented a uniformly distributed MPL microstructure without large cracks for the MPL which was prepared by bath ultrasonic technique (MPL-C). The Obtained results in H-2/air PEMFC under various cathode relative humidity (RHC), 33-100%, revealed that the performance of the MEA made by MPL-C is 20% higher than others; 504 mWcm(-2) versus 385 mWcrn(-2)at 33% RHc. More analysis by electrochemical impedance spectroscopy demonstrated that MPL ink preparation by bath ultrasonic techniques resulted a lower ohmic and charge transfer resistance in PEMFC at least in small scale MEA. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.