Deformation behavior under monotonic and cyclic compressions of porous Al specimens, whose porosities were 80 and 90%, produced by the spacer method was investigated at room temperature. The deviation in flow stress in the strain range of the plateau region was very low under monotonic compression. Also, under cyclic compression, the strain gradually increased with cycles. These deformation characteristics of the porous Al produced by the spacer method were related to a decrease in the intensity of deformation localization. From the comparison of closed-cell porous Al (ALPORAS) specimens of different sizes, it was suggested that the sample size effect is responsible for the decrease in the intensity of deformation localization under monotonic compression. However, the decrease in the intensity of deformation localization under cyclic compression was due to the uniform cell structure, which is an advantage of the spacer method, and not due to the sample size effect. Crown Copyright (C) 2007 Published by Elsevier B.V. All rights reserved.