The filtration characteristics of cross-flow microfiltration of fine particles suspended in polymeric aqueous solution are studied. Polymethylmethacrylate (PMMA) submicron particles are suspended in polyacrylamide (PAA) aqueous solution to prepare the suspensions used in experiments. Effects of operating conditions, such as cross-flow velocity, filtration pressure, and PAA concentration, on the filtration flux and the cake properties are discussed. The results show that an increase in cross-flow velocity or filtration pressure causes the filtration flux to be higher, but the filtration flux decreases with an increase in PAA concentration. Since the flow behavior indices of three prepared suspensions are almost the same, the average specific filtration resistance of cakes under various cross-flow velocities and PAA concentrations remain almost constant; and then the cake mass plays a major role in determining the filtration resistance and the filtration flux. A force balance model is derived for particle deposition on the membrane surface. Once the empirical coefficients are obtained from experimental data, the filtration flux at pseudo-steady state can be predicted accurately.