Abstract: The best conditions of immobilizing glucose oxidase using different supports and different methods were studied and compared. An improved method of glucose oxidase immobilization by glutar aldehyde was studied. One end of a glutaraldehyde molecule was first protected by die thanolamine and the other end was linked to the carrier. Then the protected end was hydrolysed and glucose oxidase was linked to it. Glucose oxidase immobilized according to the above method has the highest activity. The enzyme activity was two fold higher than the polyacrylamide and 10% higher than the diazo method.