It is significant to reduce concentration losses of Polymer Electrolyte Membrane Fuel Cell (PEMFC) in high current density range. Therefore, many researchers have studied on the oxygen depletion in the flow field of cathode side and removing produced water which have effects on the concentration losses. One of the solutions to have lower oxygen depletion along the flow channel is having higher oxygen concentration in the catalyst layer along the flow path in the cathode side. In this study, we used the serpentine flow field with dual air inlets, instead of a single air inlet in the cathode side. And we conducted the experiments for the performance comparison between the fuel cell with a single air inlet and the fuel cell with dual air inlets not only using 100% humidified air, but using dehumidified air. Furthermore based on the experimental results, we did numerical analysis for studying the factors and reasons of performance improvement of fuel cell with dual air inlets. Finally, we verified that the fuel cell with dual air inlets has relatively higher oxygen concentration in the catalyst layer along the flow path than the fuel cell with a single air inlet.