A surfactant plays a key role in the protein extraction by reversed micelles. In this study, extraction of some proteins by new reversed micelle was carried out using dioleyl phosphoric acid (abbreviated DOLPA) instead of conventional surfactant AOT. Large protein more than 50000 of molecular weight, which is difficult to dissolve into AOT reversed micelle, could be easily extracted by DOLPA reversed micelle. Denaturation of the proteins was depressed by using DOLPA reversed micelle because of the poor solubility of the DOLPA to the aqueous solution. Further, hybrid reversed micelle of DOLPA and AOT was investigated. It is found that extracted ratio of a - chymotrypsin was increased by use of the hybrid reversed micelle.