In this study, the possibility of enhancing permeability of porous Si3N4 ceramics was studied by using pore former additive (potato starch; 0-30 vol.%). The open porosity of samples changed between 52 and 66% as the mean pore channel size values ranged from 0.9 to 4 tim. Increasing starch addition provides bimodal distribution of pore size channels by accompanying abrupt increment in non-Darcian permeability. k(2) value rised from 8.7 x 10(-10) m to 30.1 x 10(-10) m. (C) 2013 The Ceramic Society of Japan and the Korean Ceramic Society. Production and hosting by Elsevier B.V. All rights reserved.