Deformation behavior of porous aluminum alloys with aligned unidirectional pores through equal-channel angular extrusion (ECAE) was investigated. The porous aluminum alloys were fabricated by dipping pure aluminum pipes into semi-solid slurry base metal. The pipes did not detach from the base metal even through the ECAE process. Comparing the sample dimension of pores before and after ECAE process, the amount of decrease in a dimension of pores was 19.4% in this study. The Vickers hardness increased by work hardening. Especially, the hardness value of area where plastic flow arose increased significantly. These results show that we can improve the mechanical properties with maintenance of the porous structure and measure the amount of the sample deformation quantitatively.