In this paper, a new method for the identification of nonlinear system composed by the Wiener and Hammerstein models connected in parallel is presented. This block‐oriented nonlinear system is a more general nonlinear model than Wiener and Hammerstein ones. The proposed nonlinear structure can easily describe the Wiener and Hammerstein models. Then, most of existing works are focused on the identification of one of the two models or the cascade connection of these two models. In this study, the parameters identification of linear and nonlinear blocks can be performed using one stage. Then, simple sine or multi‐sine waves were applied to the system input. Unlike several other methods, the linear elements can be parametric or not.