This final thesis analyzes composite materials, more precisely fiber-reinforced polymers used as one of the materials for making skis in the company Elan. In the introduction, the types and characteristics of composite materials are generally analyzed, the classification of composite materials is performed with special emphasis on fiber-reinforced polymers. The technique of making composite materials and the procedures of making composites in open and closed molds are presented. Examples of application of individual composite materials are given. In the second chapter of the final thesis, an experimental plan is given, on the basis of which nine test samples were made from fiber-reinforced polymer, where three series with three samples each were with different thickness. All samples were of nominal length 250 mm with fibers of length 50 mm. All samples were subjected to tensile testing on a tensile machine for static and dynamic tests in order to determine mechanical properties. The force and longitudinal displacement (actuator displacement) were measured on the tensile testing machine, while with the ARAMIS measuring system, deformations in the transverse direction (perpendicular to the tensioning direction) were measured. At the same time, strain gages, 6 mm and 20 mm long, were attached to six of the nine samples to determine any differences in local and global behavior. Prior to testing, the samples surfaces were analyzed with a digital stereomicroscope, at 12x, 25x, and 45x magnifications. In order to further determine the influence of the structure and size of the fibers on the mechanical properties, analysis was also performed with a light microscope at magnifications of 200x and 1000x. The results of measurements on the tensile test machine, presented in the form of stressdisplacement of actuator diagrams, are shown first within the same series (equal thickness of the test sample) and then the results are compared for different thicknesses of the test sample. By tensometric measurements using of SG6 and SG20 strain gauges, the dependence of the principal deformation ε1 on time were determined. The engineering curves σ-ε for all nine test specimens were determined using the ARAMIS measuring system and given on diagrams. At the end of this final thesis, the overall results for the modulus of elasticity, Poisson's ratio, shear modulus and tensile strength are presented. It was found that the best properties have test specimens with the greatest thickness, which also had glass fibers of knitted structure. The fracture mechanism was further confirmed by analyzing the fracture surfaces with a microscope.