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°C and stress rate for 0.1s-1 with the average grain size for 54.03μm.