This study investigated the ultrafiltration of soybean oil/hexane extract (miscella) using porous ceramic membrane. The evaporation energy can be saved in the soybean oil production by pre-separating a portion of hexane through the ceramic membrane. Raw soybean oil/hexane extract with 33wt% of oil was used without pretreatment. A cross-flow ultrafiltration was performed using an anodisc membrane with a pore diameter of 0.02μm and thickness of ~1μm. The concentrations of oil/hexane mixture were measured by UV adsorption at a wavelength of 458nm. The separation mechanism was suggested to be the hindrance diffusion of soybean oil. Agitation in the feed side significantly increased the rejection of soybean oil. A small stage cut could also yield a higher rejection. Above observations were attributed to the reduction of concentration polarization by increasing the shear rate and small permeate flux, respectively. The optimum separation was achieved under the conditions of 4kg/cm 2 transmembrane pressure, 0.04 stage cut and 120rpm agitation speed. The concentration of soybean oil decreased from 33wt% of feed to 27wt% in permeate, that is, near 20% rejection. A gel-layer polarization model was proposed to estimate the gel concentration and thickness. The gel concentration was found 43-53wt%. Agitating feed side reduced gel thickness, thus enhanced the rejection and permeate flux.