Carbon nanotubes are one of the strongest materials of unique mechanical, optical, electrical and electronic properties. Because of that they are mainly used as semiconductor materials constituting the reinforcing phase in composite materials.The paper presents properties of polymer composites reinforced with carbon nanotubes (CNT) containing various mixtures of dispersion. Produced composites featured various content carbon nanotubes: 20%, 30%, 40% i 50%. Macroscopic observations were carried out on ready to check composites, if pores exist in the structure and whether the reinforcement has been distributed in the entire volume. Bending and compressive strengths tests were performed and densities of individual composites were measured to determine the specific strength.Composite materials strengthened with carbon nanotubes feature a very low density and a very good mechanical strength, which makes them a good structural material.