Abstract: With the purpose of improving enzyme catalytic efficiency, the ionic liquid/buffer biphasic system was used as bio-catalytic medium for immobilized <em<β</em<-glucuronidase to catalyze hydrolysis of GL into GAMG. Experiments show that, under the conditions of 0.25 g amount of immobilized enzyme, 35% volume fraction of PF<sub<6</sub<, pH value of 5.0 and the reaction temperature of 40 ℃, the maximum enzyme activity can reach 1 000 U. It is well above 450 U, which was the highest enzyme activity measured in the buffer mono-phase system. The reutilizing experimental results show that the reusing rate of PF<sub<6</sub< is greater than 85%, and the immobilized <em<β</em<-glucuronidase relative activity is above 93% in the reaction medium of recycling PF<sub<6</sub<.