The object of research is epoxy composite materials with various solvents. Acetone, gasoline, solvent grade P647 and butanol were considered as solvents. The aim of the work is to establish the biological resistance of epoxy materials in marine climate conditions with the prospect of their use as impregnating compositions. Method. The biological resistance of epoxy composites was assessed by the species composition of microorganisms on the surface of the samples after they were kept for 21 months in an open area under natural and climatic conditions in Gelendzhik (Russia). The fingerprint method was used to identify microorganisms from the surface of the samples. Results. The species composition of microorganisms inhabiting epoxy composites was experimentally determined, depending on the type of solvent and the quantitative content of the hardener. Samples with solvents in their composition (gasoline and butanol) turned out to be the most resistant of the studied (30 mass parts of the solvent) to the aggressive effects of microorganisms. Compositions containing 12 mass parts of the hardener in their composition have the lowest biological resistance of the studied ones.