Abstract: The authors designed and fixed an ultrafiltration equipment in pilot plant scale with two tubular ultrafiltration modules provided by KOCH Membrane Systems Inc. , U. S. A. ,and made a lot of experiments on apple juice clarification. The affects of bulk solution velocity, average pressure,temperature and soluble solids of the juice, as single factor on permeant flux and the effect of bulk solution velocity, average pressure and temperature, three factors simultaneously on permeant flux were investigated respectively. In addition, the ultrafiltrated apple juices were anaeysed and evaluated by a test panel. The result showed that the effect of the average pressure on permeant flux was more strong, then bulk solution velocity and then temperature. But the increase of the temperature was limited by the membrane and processed juice. So if condition permits,high average pressure and bulk solution velocity should be selected. The ultrafiltrated apple juice was in high quality and sterilized.