Abstract: The reaction properties for the immobilized L aspara ginase with ethylenediamine hydroxypropyl chitosan were studied in this paper. The effects of store condition on the activity of the immobilized enzyme was inv estigated.For the immobilized enzyme,the K m value, the property of resisting protease, the bath reaction kinetics and the continuous reaction kinetics in bu ffers were studied. The results show that, under the proper react ion condition, the immobilized enzyme posseses good properties for hydrating asparagin both in batch and in continuous type.