The article presents the wood composite materials based on biodegradable component of polyvinyl acetate with the filler in a form of wood flour of pine trees of two types: unmodified and thermally modified pine. The sorption properties of composite of both species, namely the ability of a material to absorb moisture depending on the quantity and nature of wood filler were studied. The strength characteristics of composite materials with non-modified and modified wood fillers were investigated and revealed. The research of the loss of relative weight of both types of composite materials while standing in soil was conducted.The expediency of preliminary heat treatment of wood filler on politely if necessary some increase in biostability of the composite is found.