The hexagonal silica mesoporous material SBA-15 with ordered 2-dimensional channel structure was used as a support to immobilize the enzyme trypsin which was assembled in the channel of SBA-15 by immersion method. The effects of immobilization conditions such as enzyme concentration, pH value and time on the absorbed amount of enzyme in SBA-15, the thermal and operational stabilities of the immobilized enzyme were studied. And the best enzyme concentration and immobilization time were 5 mg/ml and 10 h, respectively, under which the absorbed amount of enzyme reached 23.6 mg/g. It was also found that the thermal and operational stabilities of the immobilized enzyme were higher than those of the free enzyme. Silica mesoporous material SBA-5 was shown to be a good support for immobilization of enzyme.