The　3003　aluminum　alloy　was　deformed　with　isothermal　compression　in　a　range　of　deformation　temperature　of　300-500　°C　at　a　strain　rate　of　0.0l-10.0　s-1　with　a　Gleeble-1500　thermal　simulator.　The　results　show　that　the　flow　stress　of　the　3003　aluminum　alloy　decreases　with　an　increase　in　the　deformation　temperature　or　a　decrease　in　the　strain　rate.　A　flow-stress　constitutive　model　was　build.　The　critical　strain　and　steady　strain　were　obtained　with　the　strain-hardening　rate.　The　critical　strain　increases　with　an　increase　in　the　Zener-Hollomon　(Z)　parameter,　and　the　steady-state　strain　decreases　with　an　increase　in　the　Z　parameter　(a　decrease　in　the　deformation　temperature　or　increase　in　the　strain　rate).　A　dynamic-recrystallization　(DRX)　state　diagram　was　established　in　accordance　with　the　eigenvalues　of　the　flow-stress　curve.　Based　on　a　microstructure　observation,　it　was　found　that　the　smaller　the　Z　parameter　and　the　greater　the　strain,　more　complete　was　DRX.　©　Institute　of　Metals　and　Technology,　Ljubljana,　Slovenia.