Fouling behaviors in membrane filtration of dilute suspension of polystyrene latex (PSL) were examined under constant-pressure conditions using diatomaceous ceramic membranes which are semi-permeable to the PSL. Flux decline behaviors were evaluated in consideration of the effect of the solid permeation through the membrane. The conventional characteristic filtration equation was modified by applying the Kozeny-Carman equation to the filtrate,flow through the membrane pores. In the model, the porosity and specific surface area of the membrane were represented by unique functions of the solid deposit retained in the membrane pores. The variations of the filtration rate and filtrate volume with the filtration time were accurately described based upon the modified characteristic filtration equation. It was revealed that the extent of the membrane blocking per unit deposit load increased with the decrease in the pore size of the membrane and with decreasing pressure, hut was little influenced by the suspension concentration. (C) 2009 American Institute of Chemical Engineers AIChE J, 56: 1748-1758, 2010