Abstract: Papain was immobilized on modified ceramic particles and the factors related with the activity of the immobilized papain on ceramic particles were studied. The results showed that the optimum conditions were as follows: concentration of hydrochloric acid was 0.20 mol·L – 1 ，coupling agent KH-570 mass fraction was 0.392％，coupling agent glutaraldehyde mass fraction was 0.25％. In this condition，the recovery ratio of activity of immobilized enzyme was 7.16％，and the relative activity was 9.90％.