Abstract: With cross act, the optimial immobilization conditions of a kind of bacteria were obtained. Then, the phenol-degradation process of the immobilized cells observed and the kinetic parameters were analysed. Result shows that the phenol-degradation process of the immobilized cells fit in Monod model, and the degradation performance of the immobilized cells is obviously superior to that of the free cells. Meanwhile, two kinds of methods. one is to add to diatomite and the other is to do surface chemical treatment, are primarily studied to improve the character of the immobilized cells.