In　order　to　optimize　the　geometry　of　the　M-like　flow　field,　numerical　simulations　were　performed　by　virtue　of　the　fuel　cell　module　in　ANSYS　(R)　FLUENT　(R)　software　package.　Two　geometrical　parameters　of　the　M-like　channel,　namely　height　and　width　of　elliptic　obstacle,　were　considered.　Based　on　the　exhausted　numerical　results　in　the　study,　it　has　been　found　that　the　M　-like　channel　exhibits　more　uniform　and　large　molar　concentration　distribution　of　oxygen　at　the　interface　between　catalyst　layer　and　gas　diffusion　layer　in　the　cathode　side　than　the　conventional　parallel　channel.　Therefore,　more　reactants　can　participate　in　the　electrochemical　reaction　in　the　catalyst　layer,　which　improves　the　performance　of　proton　exchange　membrane　fuel　cell　(PEMFC).　Furthermore,　effective　evaluation　criterion　(EEC)　was　utilized　to　evaluate　the　comprehensive　performance　of　PEMFC　with　the　M-like　channel.　Comparing　with　the　parallel　channel,　the　M-like　channel　has　better　mass　transfer　performance　without　the　penalty　of　high　pressure　drop,　indicating　better　comprehensive　performance.　For　the　practical　applications,　optimum　height　and　width　of　obstacle　were　obtained,　the　performance　of　which　is　16%　higher　than　the　parallel　channel.