The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn2+ and H2O2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H2O2. When the amount of the immobilized H2O2 is sufficient, the microemulsion-based gels containing MnP could be used many times.