The topic of this paper is the implementatiton of a modal analysy of a steel cantilever beam in order to obtain its dynamic parameters, which are modal shapes, natural frequencies and damping coefficients. The modal forms and natural frequencies were obtained by experimnental modal analysis, and the obtained results were compared with those obtained in numerical modal analysis. We have been using the Laboratory for Vibration an Noise at the Technical Faculty in Rijeka with all available and necessary equipment for the experimental test. „Ansys“ program was used for the numerical results of the modal parameters The first part of the paper describes the foundations of modal analysis and her division and for what purpose is being used. Modal parameters were also described and obtained with the help of modal analysis. A formula for obtaining natural frequencies was also derived. The Euler-Bernoulli theory for beams is describen and derived, and forms of vibration are described and given. All the necessary elements for performing the experimental test are described in detail, both for this case and for other cases. The obtained results of natural frequencies of two cantilever beams with diferent materials, which are obtained by numerical modal analysis with the help of „Ansys“ program were compared and analyzed.