The crossflow microfiltration process was experimentally investigated with four kinds of particle suspensions to clarify the effects of both cake-compressibility and operational variables on the filtrate flux. The experimental results of filtration rate for incompressible cake(microsilica, polystyrene latex) and moderate compressible cake(yeast) show the usual filtration behavior, namely increasing crossflow velocity and/or transmembrane pressure increases in the filtration rate. On the other hand, with a highly compressible cake such as agar-agar gel, the filtration rate results in a remarkable reduction with increasing transmembrane pressure, because of the irreversible behavior of the cake structure. Furthermore, the crossflow microfiltration process is analyzed based on a model formulated by incorporating the particle adhesion probability information together with the conventional cake filtration theory. The calculated results coincide favorably with the experimental results of crossflow microfiltration for an incompressible cake.