ASTM　A240/A240M　304　structural　stainless　steel　is　a　widely　used　structural　material　in　civil　engineering.　In　this　study,　by　using　the　split　Hopkinson　pressure　bar　(SHPB)　technique,　the　dynamic　compressive　mechanical　behavior　of　this　material　was　experimentally　investigated　at　four　different　temperatures　of　25　degrees　C,　300　degrees　C,　500　degrees　C,　and　700　degrees　C　and　three　strain　rates　of　1,000,　3,000,　and　5,000　s-1.　Quasi-static　compressive　test　under　the　strain　rate　of　0.001　s-1　was　also　carried　out　in　the　material　test　system　at　temperatures　of　25　degrees　C,　300　degrees　C,　500　degrees　C,　and　700　degrees　C.　Test　results　showed　that　flow　stress　of　ASTM　A240/A240M　304　stainless　steel　decreases　with　temperature　increase　but　increases　with　increase　of　strain　rate.　Moreover,　temperature　becomes　the　main　factor　affecting　material　performance　at　700　degrees　C.　Based　on　the　measured　stress-strain　curves,　the　modified　Johnson-Cook　model　was　proposed　as　the　constitutive　stress-strain　model　for　ASTM　A240/A240M　304　stainless　steel.　It　was　shown　that　the　proposed　modified　Johnson-Cook　model　is　in　good　agreement　with　the　experimental　results.　According　to　the　proposed　modified　Johnson-Cook　model,　a　user　subroutine　(VUMAT　for　Abaqus/Explicit)　for　ASTM　A240/A240M　304　written　in　Fortran　was　developed　and　verified.　The　proposed　constitutive　model　and　user　subroutine　of　ASTM　A240/A240M　304　stainless　steel　can　be　used　for　structural　analysis　and　finite-element　analysis　under　high　strain　rates　and　elevated　temperature.　(c)　2020　American　Society　of　Civil　Engineers.