Abstract: The paper presents the results of the theoretical investigations of the finite amplitude plane wave propagation problem. The case of harmonic plane pressure wave of megahertz frequency propagating in water is discussed. Mathematical model and some results of numerical calculations are shown. The nonlinear acoustics equation was considered to build the mathematical model. To solve the problem numerically the finite-difference method was applied. The influence of discrete model parameters on the numerical calculations accuracy was studied. The results of computer calculations for different values of physical parameters were also analyzed.