Exponential-sinusoidal models are considered in this wok. The main attention is given to estimation of nonlinear parameters (damping coefficients and frequencies) of these models. The results of estimation of the considered parameters by Prony and Levenberg methods are analyzed. The conclusions on possibilities and restrictions of these methods are presented. The description and program codes of the software developed are given. The software is intended for generating of exponential-sinusoidal models and estimating by Prony and Levenberg methods.