The permeate fluxes of an inclined gas-slugs ultrafiltration system were measured and discussed under various gas-liquid flow ratios and inclination angles. The experiments were carried out in a tubular ceramic membrane module by using dextran T500 aqueous solution as the tested solution. In the single liquid-phase ultrafiltration system or the gas-liquid two-phase ultrafiltration system with turbulent liquid flow, the variation of inclination angle affects the permeate flux slightly. In the gas-liquid two-phase ultrafiltration system with laminar liquid flow, the permeate �ux is enhanced significantly as the inclination of the ultrafiltration column increases up to a certain angle. The optimal inclination angle of the ultrafiltration column is about 538 in present experimental system. The enhancement in flux is due to the combination effects of natural convection and forced convection induced by the slug flow in the inclined tubular membrane.