Effect of few-layer graphene on mechanical properties is investigated for aluminum (Al) based composites with different volume fraction of graphene. Al/few-layer graphene composites are produced by hot-rolled of ball-milled powders. Few-layer graphene prepared by the mechanical exfoliation of graphite flakes are attached to Al powder using a low energy ball milling, and then graphene are embedded and dispersed in the Al matrix using a high energy ball milling. Few-layer graphene with 100 nm in long axis and 5 layers thick play a great role as reinforcing agent in the Al matrix by obstruction of dislocation movements and grain growth in the composites. Therefore, the yield strength increases with increasing content of the graphene which demonstrates efficient load transfer between the Al matrix and graphene. The result can be suggested being the wider applications of graphene with improvement in mechanical properties of the composites.