The extraction and back extraction of Bovine Serum Albumin (BSA) using a new reversed micelle system of CTAB/isooctane/1-pentanol have been investigated. Under the optimal operating conditions in this study, the extraction ratio of BSA reaches as high as 98%. The back extraction ratio can reach 80% as pH in stripping phase approaches to the isoelectric point (pI) of BSA. UV-spectra indicated that there was no significant change in the structure of BSA enriched in stripping phase. Furthermore, the reversed micelle system was repeatedly used to extract BSA from a mixed solution of protein.