In recent years, there has been an increasing interest in composite materials reinforced with natural fibers. Due to the easy and cheap methods of obtaining raw materials, the possibility of recycling, biodegradability, production and processing safe for health, such materials can be a good alternative to composite materials reinforced with glass or carbon fibers. However, due to the lower mechanical properties of natural composites, their use as construction materials is still limited. Nevertheless, natural fiber composites have characteristics that can be used in structural applications as long as the mechanical behavior is well understood, reliable and predictable. The paper presents the results of numerical calculations of the compression process of a composite reinforced with a fabric made of flax and jute fibers (trade names: Biotex Flax 400g/cm2 and Biotex Jute 400 g/cm2) on a basis of Kinetix R240 epoxy resin. The data necessary for the numerical analysis were calculated in the Digimat software using the Double Inclusion micromechanical model, while the simulations of compression of the details were carried out in the Ansys software. Sections with different number of layers were tested. The results were compared with the experiment. Buckling forces obtained in the numerical analysis are nearby experimental results. Two types of C – section buckling modes were obtained and they consisted of two or three half-waves of buckling.