Sobol　sensitivity　analysis　can　quantify　the　impact　of　input　parameters＇　variations　on　the　performance　of　plate-fin　heat　exchanger　to　guide　the　selection　of　input　variables　during　design　procedure.　In　this　paper,　the　Reynolds　number　Re,　fin　height　h,　fin　space　s,　fin　thickness　t　and　interrupted　length　I　are　considered　as　five　input　parameters,　while　exchanger　volume,　exchanger　material　content,　heat　flow　rate　and　pressure　drop　with　different　constraints　are　taken　as　the　design　objectives.　Moreover,　to　study　the　impact　of　Brandt　number　on　input　parameters,　the　Sobol　sensitivity　indices　of　five　parameters　are　compared　for　air　and　water.　The　results　show　that　the　Reynolds　number　Re　and　fin　spaces　are　the　two　main　factors　that　affect　the　performance　of　plate　fin　heat　exchanger.　As　the　heat　exchanger　size　limited,　a　smaller　fin　thickness　t　is　selectable.　Compared　with　air,　the　interrupted　length　l　should　be　selected　a　smaller　value　for　water.　Guidance　about　the　fin　surface　selection　is　given.　Sobol　sensitivity　analysis　methods　can　be　performed　to　detect　the　importance　of　parameters　in　various　complex　engineering　applications.　And　compared　with　other　optimization　algorithms,　this　method　is　simple　to　implement.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.