The microhardness method was used to achieve plastic deformation in grain scales in polycrystalline pure aluminums. Characteristics of the deformation structure near indentations were investigated before and after annealing. The different morphologies of slipbands near indentation areas were viewed only after annealing. Within the slipband areas the numerous orderly arranged ends of the dislocations were identified. During experiments, we observed the phenomenon of slipbands across aggregate areas in grains. We discuss reasons for not discovering recrystallization in the deformed specimen after annealing. We also discuss factors such as temperature and time of annealing, reduction and grain orientation, which have influence on the formation of slipbands. The experimental results show that, being different from global deformation for materials, the mode of transgranular deformation can be used conveniently to study the morphological features of deformation and recrystallization of polycrystalline materials and related influencing factors. 