Microstructure　evolution　behavior　of　1235　aluminum　alloy　under　different　deformation　conditions　was　studied　by　hot　compression　simulation,　along　with　OM,　TEM.　The　law　of　microstructure　evolution　at　hot　deformation　was　also　analyzed.　The　results　showed　that　the　dynamic　recrystallization　behavior　of　1235　aluminum　alloy　was　obvious　during　hot　deformation.　At　higher　deformation　temperature　or　lower　strain　rate,　the　grain　dislocation　density　was　lower　and　grain　boundaries　tended　to　be　straighter,　therefore,　the　grains　dynamic　recrystallized　more　adequately.　The　recrystal　grains　were　smaller　and　distributed　uniformly　at　deformation　temperature　for　400　degrees　C　and　stress　rate　for　0.1s(-1)　with　the　average　grain　size　for　54.03　mu　m.