The article presents description of parametric identification process of agricultural unit model. It is a 2D (flat) model based on the so-called bicycle models that are often referenced in the literature. The minimization of loss function is used as identification method. The function depends on difference between results obtained by simulation and by identification experiment. The identification test was described in short. Problem of optimization algorithm selection and the problem of identification of loads acting on the vehicle while in motion were presented. Some results of identification were also presented.