Abstract: The composite material, which is a solid porous carrier, whose pores are filled with a polymer, a polyolefin having the molecular weight not less than 300,000, the degree of pore filling with said polymer being at least 4 percent of the total volume of the pores, in which the ratio of the carrier mass to the mass of the polymer is 50-99.5:50-0.5. The method of producing said composite material consists in precipitation, from the gas phase, of a complex organometallic catalyst consisting of a compound of a transition metal and of an organic compound of a metal in the 2nd or 3rd group of the Periodic Table, inside the pores of a solid porous carrier, and in polymerization of olefins from the gas phase on said catalyst, precipitated in the pores of the solid porous carrier, at a temperature of 50.degree.-165.degree. C. and a pressure of 1-60 atm. The composite material is characterized by high mechanical strength (compression strength reaching 100-200 kg/sq. cm) high frost resistance, and hydrophobic properties.