In this work we studied the influence of basalt fibers of different length on physical and mechanical characteristics of wood - polymer composites based on polyvinyl chloride. The studies showed that the most effective length of the fibers is 6.4 and 12.7 mm, and the bending strength increased by more than 30 %, and abrasion during abrasion decreased on average by 25 %. The proposed wood - polymer composites can expand the range of manufactured products on their basis.