Abstract: The UF membranes of microporous hollow fiber were used to study the distribution of the membrane resistance in the process of extracting soybean oligosacchrides. According to the flux measured under different conditions,the membrane resis- tance of every part and its ratios of the part to total resistance were calculated. The experimental results showed that the different conditions of pretreatment and ultrafiltration would have caused differences of the membrane resistance. Less concentration polarization resistance would be expected for a better pretreatment, and total resistance could decrease correspondingly.

Key words: microporous hollow fiber, soybean oligosacchrides, membrane resistance