Two kinds of parabolic mild-slope equations are studied systematically. By numerical modeling wave transformation over four typical topographies, the accuracy of numerical schemes, the effect of grid number on the solution accuracy, the sensitiveness of the models to the incident wave angle and the effect of weakly nonlinear terms on the numerical results are discussed in detail. These results can give some theoretical guidance to the applications of parabolic mild slope equations to wave propagation over complex topography in large coastal areas.