Lattice Boltzmann method（LBM）is used to investigate the effects of gas channel（GC）wall wettability on liquid water distribution and content in gas diffusion layer（GDL）of a proton exchange membrane fuel cell（PEMFC）.The effects of GC wall wettability are explored by simulating liquid water transport process in GDL and GC.Simulating results reveal that GC wall wettability significantly affects liquid water amount in GDL.Compared with hydrophobic GC，a hydrophilic GC leads to less liquid water accumulated in the GDL.A better understanding of the results is obtained by analyzing the pore-scale dynamic behaviors of liquid water with special attention given to that at the GDL-GC interface.The simulation results suggest that in future study of liquid water transport and distribution in the PEMFC，effect