LiP of Phanerochaete chrysosporium was chemically modified with MPSS, and acetic and benzoic acid N-hydroxysuccinimide esters to increase the activity in organic solvents. IEF demonstrated the LiP was chemically modified with these modifers. The modification of LiP was also confirmed by GFC and anion-exchange chromatography analyses. In addition, the modified LiP retained its original activity in aqueous solution. Furthermore, these modified LiPs had higher 3,3'-dimethoxybenzidine oxidation activity than the native LiP in aqueous 70% water-miscible organic solutions including ethylene glycol and diethylene glycol. However, the activities of these modified enzymes were found to be negligibly low in water-immiscible organic solvents such as benzene and toluene. Furthermore, the effects of these introducing groups and the properties of organic solvents on the reaction of LiP in water-miscible organic solvents were investigated. The reaction of LiP modified with aliphatic acid was found to depend on the viscosity of the reaction system containing 70% water-miscible organic solvents. This suggests that the viscosity of the reaction system containing water-miscible organic solvents is important for the reaction of LiP modified with aliphatic acids.