The　effect　of　inclusions　on　the　softening　mechanism　of　a　pure　aluminum　alloy　is　studied　with　TEM,　EDAX　and　SAED.　Oxide　inclusions　and　iron-rich　second-phase　particles　are　the　main　inclusions　in　Al　1235　alloy.　The　phase　of　iron-rich　particles　in　the　alloy　is　phase　AlFe3　with　a　lattice　constant　of　5.79　and　crystal　band　axis　of　[231].　During　thermal　deformation,　coarser　inclusions　in　the　alloy　are　beneficial　to　the　nucleation　of　dynamic　recrystallization,　but　they　have　a　great　effect　on　the　separation　of　the　alloy　matrix.　Nucleation　and　growth　of　dynamic-recrystallization　grains　are　restricted　by　finer　inclusions,　reducing　the　possibility　of　aluminum-matrix　fracture.　The　preferred　places　for　dynamic-recrystallization　nucleation　include　boundaries　at　the　intersection　of　three　grains,　the　dislocation　plug　area,　the　surface　of　the　coarse　oxide　inclusions　or　the　coarse　second-phase　inclusions.