Abstract: We introduce the Lax-Wendroff difference method into the calculation of interconnect transmission lines.An efficient Lax-Wendroff difference scheme with second order accuracy is proposed by considering the structure characteristic of telegrapher's equations.Numerical experiments are presented and the results are compared with that computed by the methods of characteristics and fast Fourier transform(FFT).The approach of direct time-space discretization can be applied to analyzing general interconnect transmission lines including non-uniform transmission lines.The efficiency of the proposed method is close to that of methods of characteristics but its application scope is wider.