A simple and accurate numerical local-potential-averaging (NLPA) method is presented for calculating both the eigenstates of the Schrodinger equation and the quantum transport properties based on the Wigner distribution function. This method can handle the abrupt discontinuities in the potential profile of nano-scale electronic devices quite successfully that the accuracy of the numerical finite difference calculations combined with this method is less sensitive to the size of grid spacing along the discretized coordinate and thus. we can maintain the same level of numerical accuracy of the conventional method with much sparser grid points which make numerical computations less intensive. (C) 2004 Elsevier Ltd. All rights reserved.