This paper presents a novel approach for estimating the Saleh model’s parameters using the gain and third-order intercept point (IP3) of a power amplifier. The IP3 is a widely used technical parameter for describing the nonlinearity of the power amplifier in wireless communications. The proposed approach minimizes an objective function of error between the third-order Taylor series and the Saleh Amplitude-to-Amplitude (AM/AM) model. This approach of the parameters estimation is also used for identifying the Digital Predistortion (DPD) to compensate for the memoryless AM/AM nonlinear distortion of power amplifiers in wireless communications. Finally, the Saleh model accuracy and DPD linearization are validated based on the WCDMA measurement signal.