The results of aging behaviors of ultra fine grained Al-Si alloys and Al-Si-Ge alloys fabricated by the accumulative roll bonding (ARB) process were overviewed. It was clarified that the precipitation behaviors during aging treatment of of the ARB processed Al-Si and Al-Si-Ge alloys significantly depended on the concentration and kind of alloy elements (Is, Ge) and aging conditions. It was considered therefore that the alloy design and the selection of appropriate heat treatment conditions are important for applying the ultra fine grained Al alloys. The ARB process used in this study is an advantageous severe plastic deformation process for practical applications, since it uses the rolling deformation that is the most preferable metal working process for continuous production of bulky sheet materials. The combination of ultra grain refinement of the Al matrix and subsequent age hardening realized superior materials having higher strength than the same alloys with coarse-grained matrix structure after the aging treatments.