Magnetic cross linked enzyme aggregate of glucose isomerase were prepared by chemical cross-linking of enzyme aggregates with amino functionalized magnetic particle. The result of X-Ray Diffraction (XRD) has shown that the particles are in hematite phase (Fe2O3) and 47.84nm in size. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the existence of the surface coating. Scanning probe microscopy (SPM) was used to confirm the presence of protein on the particle surface. The magnetic CLEAs displayed a shift in optimal pH towards the acidic side, whereas optimal temperature of magnetic CLEAs was shifted to higher temperature, making conditions favorable for commercial use. Moreover, the magnetic CLEAs retained 80% initial activity even after 6 cycles of reuse.