A theoretical model to simulate an end-pumped CW Nd^3+:GdVO4 laser at 1063 nm is presented. Its essence is to use the propagation equations to demonstrate the spatial evolutions of the pump and the laser powers in the cavity, hence it is applicable to both low and high gain lasers. The simulation results obtained by this model are in good agreement with the experimental observations reported in the literature for a Ti:sapphlre-pumped Nd^3+:GdVO4 laser. Moreover, some parameters, such as the reflectivity of output coupler, the spot size of laser beam and the crystal length, are discussed with a view to optimizing the laser performance.