Abstract: Separation processes with ultrafiltration and nanofiltration were introduced to purify and concentrate the fiber-board filtered lincomycin broth in front of mixed-alcohol extraction.Bench scale test indicated that the application to the alkalized feed was superior to the non-alkalized feed.After comparing several membranes with different materials(PES,PS,PA) and molecular weight cutoffs,PES-10 and NF-270 were found to be the optimum UF and NF membranes.Successive extraction after UF-NF needed less extractant due to the reduced feed volume.Both the extraction efficiency and product yield were improved.For NF concentration multiple of 1.28,the mixed-alcohol once-extraction rate and the general product yield increased by 4.3% and 3.4% respectively.The color of extract phase was lighter than the ones without UF-NF.