The　shear　buckling　behaviour　of　welded　stainless　steel　plate　girders　with　transverse　stiffeners　has　been　experimentally　and　numerically　investigated　in　this　paper.　A　total　of　seven　plate　girders　with　rigid/non-rigid　end　posts　were　fabricated　from　hot-rolled　stainless　steel　plates,　and　each　of　the　plate　girders　was　subjected　to　a　concentrated　load　at　mid-span.　The　shear　buckling　characteristics　and　postbuckling　behaviour　were　observed.　Prior　to　testing,　the　initial　local　geometric　imperfections　and　the　material　properties　were　accurately　measured.　The　critical　shear　buckling　strengths　of　the　web　plates　were　determined　from　the　recorded　surface　strains　and　out-of-plane　deflections,　which　were　further　compared　with　theoretically　predicted　values　from　elastic　and　inelastic　assumptions.　By　using　the　general　finite　element　(FE)　software　package　ABAQUS,　elaborated　FE　models　were　developed　and　validated　against　the　obtained　test　results　and　other　available　existing　test　data.　Upon　validation　of　the　FE　models,　parametric　studies　were　subsequently　carried　out　to　explore　the　influences　of　initial　local　geometric　imperfections,　web　aspect　ratios,　end　post　conditions,　and　material　properties　over　a　wide　range　of　web　slendernesses.　The　obtained　test/FE　results,　together　with　other　existing　test　data,　were　summarised　to　evaluate　the　current　codified　provisions　in　GB　50017,　EN　1993-1-5,　EN　1993-1-4,　EN　1993-1-4　+　A1　and　the　design　proposals　from　Estrada　et　al.　Based　on　the　test　and　numerical　results,　an　alternative　design　approach　that　could　account　for　the　material　non-linearity　and　rigid　and　non-rigid　end　posts　has　been　proposed,　which　provides　accurate　and　reasonable　strength　predictions　for　stainless　steel　plate　girder　with　transverse　stiffeners.