ABSTRACT This paper treats the standing waves formed by two progressive waves possessing same properties but opposite direction in stationary atmosphere and uniform depth. The third-order approximation to two-wave trains interactions obtained by Chen¡]1990¡^is cited. From the solution that can be reduced to the cases such as standing waves, the properties resulted in standing wave due to the nonlinear interactions between two wave trains intersection, particularly, the two peaks of wave pressure, are described clearly. Furthermore, the profile, pressure and angular frequency is also verified in good agreement with the experimental results.