Abstract: This paper studies on the continuous hydrolysis of urea by proleus Morganii cells with the wbean-producl aste ater as nutriment in the biological reactor. Its lesults show that v hen cells grow in the bean-product wastevater at 37℃, the true growth yield factor is 5.43mg bacterium per mg protein and the maintenance coefficient is 0.018(h-1).It is demonstrated that the cells need dissolved oxygen in gro ing condition, but oxygen is not necessary for cells to hydrolyze urea. In order to keep the process of urea hydrolysis by cells, the adequate supplies of nutriment and dissolved oxygen are essential.It is also demonstrated that the cells have leng stability of urea hydrolysis in the bean-product waslewater by continuous 100(h) experiment. We have selected PSA membrane of ultrafiltraticn to concentrate the suspension solution and return the concentrated solution into reacting system. Experimental results show that this method can raise largely urea decomposition ratio(ε).Thus the method of urea hydrolysis by biological treatment and membrane separation is possible to treat industrial urea wastcwater.