Porous alumina with the surface layer was fabricated from an alumina platelet/novolac-Hexa Methylene Tetramine (HMT) composite. HMT was used as a blowing agent as well as a curing one for the novolac binder. When the alumina platelet/novolac composite was heated with covering its surface with filter papers, a porous structure formed inside the composite due to blowing from HMT. On the other hand, the blowing gas near the surface was evolved outward through the filter paper, which resulted in the formation of the surface layer composed of the aligned alumina platelets. Effect of the surface layer on the mechanical strength was examined by three-point bending measurement. The bending strength of the obtained porous alumina increased by 94% compared to the porous alumina without the surface layer. (c) 2017 The Ceramic Society of Japan. All rights reserved.