Wood/plastic composites are reviewed focusing on background, preparative methods, properties, and industrial activities. Several materials with high content (70∼95 wt%) of wood fiber, wood flour, and/or wood particles, bonded with a thermoplastic polymer such as polypropylene, will shortly be prepared by extrusion molding on a commercial scale. These materials are expected to contribute to recycling of waste wood and to the preparation of a new type of wood-based materials.