In this study, we present a novel catalyst layer (CL) with in-plane flow channels to enhance mass transports in polymer electrolyte membrane fuel cells (PEMFC). The CL having in-plane channels on its surface is fabricated by coating a catalyst layer slurry on a substrate with line pattern and transferring the dried CL from the substrate to a membrane. The membrane electrode assembly (MEA) with the in-plane channel-patterned catalyst layer (IC-CL) shows superior power performances in high current densities investigated compare with conventional flat CL (FCL), indicating significant enhancement in mass transport by the IC-CL. The performance increase is more pronounced when the channel direction is perpendicular to the flow field direction, indicating that the in-plane channels increase the utilization of the CL under land area. Simulation results show that Knudsen diffusion in the CL is facilitated in the presence of the channels. These reasons demonstrate that role of the pattern is same as channel at the bipolar plate and further experimental results show that, additional in-plane direction of channel at CL enhance the mass transport.