Urease fromjack beanmeal (E.C. 18.104.22.168)was immobilized in calciumalginate beads. Effects of varying alginate and CaCl2 concentration on immobilization yield were examined. The influence of pH, temperature and enzyme matrix ratio on the percent of the immobilization and activity was studied. An inhibiting effect ofmercury (Hg2+) and copper (Cu2+) ion on immobilized urease has been investigated in order to elucidate the kinetics and mechanismof inhibition. Optimumsodiumalginate and CaCl2 concentration were found to be 2% (w/v). An increase in the concentration of alginate gives rise to a reduction in membrane thickness, while an increase in the concentration of calcium chloride leads to the formation of a thicker film. The straight lines intersecting at x-axis shows noncompetitive inhibition for both the Hg2+ and Cu2+.