Fine particles of iron oxide have been widely studied and used as magnetic materials. One of viability is to use iron oxides as magnetic carriers. Movement of magnetic particles could be controlled by external magnetic field. They may be applicable in medical science like as Drag Delivery System (DDS). In this study, delta-FeOOH were synthesized and used to immobilize glucose oxidase on the surface as a model. The immobilization and enzymatic reaction were studied by UV-VIS spectrometer.