In this paper , a neural network approach is made to the concentrator location problem ( CLP) in the design of local access network. The goal of this NP-complete problem is to minimize the total cost associated with capacitated concentrators and to apply the lagrangian method and the differential equation of the neural network dynamic system made of penalty functions. In this paper, the problem is efficiently solved by the special neural network. Several simulation results show that the neural network approach is desirable in finding better solutions or optimal solutions.