The performance of the submerged membrane filtration system was investigated under various aeration rate and membrane inclination. The teat solutions were the aqueous solutions of PMMA and dextran T500. Experimental results show that aeration enhanced the permeate flux of PMMA solution more significant than that of dextran T500 Solution. In the two solutes system, dextran T500 was the major role on influencing the flux behavior of the filtration system even the concentration of dextran T500 is low. Aeration is an effective way to disturb the concentration polarization layer and reduce the filtration resistance. The filtration performance can be further improved as the membrane inclination is changed from the vertical position (90 degrees) to an inclined position (160 degrees).