Abstract: Porous SiC ceramic filters with different thickness and apparent porosities of 39.2%, 48.9%, 54.4%, respectively, were sintered at 870℃ for 2 h by changing the content of petrol coke powder (as the pore former). The micromorphology and phase composition of the ceramic filters were analyzed by the scanning electron microscope, energy dispersive spectroscope and X-ray diffraction. Moreover, the effects of thickness and apparent porosity on the water permeation flux of the ceramic filters were investigated by the dead-end filtration. The results show that the microscopic pores distributed uniformly in the porous SiC ceramic filter. With the increase of the filter thickness, the water permeation flux of the ceramic filter showed a linear decrease trend, and with the thickness over 8 mm it would be very difficult for water running through the filters. At the same thickness, with the increase of apparent porosity, the water permeation flux increased rapidly. The influence of the apparent porosity on the water permeation flux was bigger than that of the filter thickness.