The article considers the bioproofness of a new composite paper-poly-para-xylylene (parylene) coating as compared with a composite paper-polyethylene, widely used in restoration practice. The intensity of paper deterioration by fungi was estimated simultaneously by several methods: by loss in mass, by consideration of cellulose decomposition (carbohydrates) and by means of electronic microscopy. The data showed that parylene coating, the same way as polyethylene one, was not used as the only source of carbon by employed fungi species. The protective effect of these films was comparable and comprised 13-74%, depending on a film kind, paper sort and an activity of a biodestructor.