Lactase is a very important enzyme to cure lactose intolerance problem. However, it is naturally existing in soluble form and cannot be reused. The current study was performed to compare the productivity and stability of lactase immobilized on calcium alginate and magnetic chitosan. The reusability of immobilized enzyme was measured for 28 days. Thermal stability was measured at 27, 37, 50 and 70 degrees C. Lactase immobilized on calcium alginate showed a better stability after 21 days where it retained up to 62% of enzyme activity. However, lactase on magnetic chitosan expresses a better thermal stability as it produced 6% more sugar than lactase on calcium alginate at the optimum temperature 50 degrees C. Lactase immobilized on calcium alginate and magnetic chitosan showed significantly different enzymatic activity, stability, and reusability.