The objective of this paper is to use the Independent Component Analysis technique (ICA) in the Operational Modal Analysis (OMA) in order to determine the modal parameters of a half car model with four degrees of freedom. The ICA method is a major technique of the Blind Source Separation (It considers the studied system as a black box and knowing only its responses it can estimate its modal parameters) which is based on the inverse problem. In our case, this technique can be used to reconstruct the modal responses of the half car model knowing only its vibratory responses. In this paper, these vibratory responses are numerically computed using the Newmark approach and they constitute the observed signals for the ICA algorithm. So that based only on the knowledge of these responses, the ICA estimates the modal characteristics (modal responses, eigenfrequencies) of the studied half car model. Finally, the modal responses of the studied system obtained by the classical modal analysis are compared with those estimated by the ICA technique using some performance criteria which are the Modal Assurance Criterion (MAC number) and the relative error. The obtained results show a good agreement between the theoretical and estimated modal characteristics.