Polymeric composite materials (PCM) based on polyester resins are widely used in various branches of modern technology. PCM has several advantages compared to metals, concrete, and glass are often effective alternative to the traditional structural materials. The main advantage of PCM is a high level of specific characteristics. Processes of formation of products from PCM let you receive the product more sophisticated form and are characterized by a much lower power consumption. These advantages apply to a new class of polyester granular RMB – injection artificial stone (LIC), intended to replace the natural granite, marble and other rocks in the construction and mechanical engineering. Replacing traditional materials to composites it is accompanied by a significant amount of scientific research related to the study of the characteristics of the mechanical behavior of FRP. At present there are limited studies of mechanical characteristics of LIC needed to assess the structural elements of the performance of these materials. This paper presents the results of an experimental study of mechanical properties of LIC unsaturated polyester used in various fields of modern technology and construction. Obtained stress-strain diagram and the compression of the material, the curves of creep and stress relaxation in tension. The fracture toughness of the material is determined by the results of the compliance testing of samples – the central beam with edge incisions. A comparison of mechanical properties of the material obtained under different kinds of tests.