The hydrophobic microporous layer (MPL) coated on the gas diffusion layers (GDLs) have been commonly used to improve water management properties of polymer electrolyte fuel cells (PEFCs). An MPL coated GDL designed to prevent dehydration of the membrane electrode assembly (MEA) under low humidity conditions is generally inferior at reducing flooding under high humidity conditions. Thus, developing an MPL coated GDL to enhance the PEFC performance under low and high humidity conditions is crucial. One method to overcome the defects of pure hydrophobic MPL is to make double and triple MPLs, in which a thin hydrophilic layer coated on the hydrophobic MPL. Another method is a hydrophobic MPL containing hydrophilic carbon nanotubes (CNTs). Both methods effectively conserve membrane humidity and reduce flooding under high humidity conditions.