Computer simulation of the square scheme under cyclic voltammetric conditions has been carried out by the network method. This paper shows a network model for the four-member square scheme coupled with homogeneous cross-reaction, where the charge transfer reactions obey the Butler-Volmer equation. With this network model and the electrical circuit program PSPICE, the influence of both the kinetic parameters and different diffusion coefficients of the species involved on the cyclic voltammograms is examined.