A　better-designed　flow　channel　can　enhance　the　mass　transfer　and　improve　the　performance　of　a　proton　exchange　membrane　fuel　cell.　An　orientated-type　flow　channel　can　achieve　guidance　on　reactant　and　product　transfers,　resulting　in　an　increase　in　the　mass　transfer　flux　and　the　rapid　removal　of　the　product　(especially　liquid　water).　In　this　study,　flow　fields　with　different　orientated-type　gas　flow　channels　having　different　baffles　are　fabricated,　and　their　effects　on　the　current　density　outputs　of　proton　exchange　membrane　fuel　cells　under　various　heating　temperature　and　reactant　flow　rate　conditions　are　investigated　using　a　self-constructed　testing　system.　The　experimental　results　indicate　that　cell　performance　can　be　increased　when　using　orientated-type　flow　channels　with　baffles　having　longer　leeward　sides,　and　cell　performance　is　increased　more　under　a　suitable　heating　temperature.　Moreover,　the　increase　in　the　current　densities　of　proton　exchange　membrane　fuel　cells　with　smaller　baffles　is　limited　when　increasing　the　reactant　flow　rates.　This　limitation　can　be　avoided　when　using　the　orientated-type　flow　channels　with　baffles　having　longer　leeward　sides.　(c)　2020　American　Society　of　Civil　Engineers.