Although a great amount of wood is in use in Japan, a little attention has been paid to the significance and importance of wood preservation. The fact reflects that only less than 0.5% of the total wood consumption is treated with wood preservatives today in the country. Over the 20 years before 1970, the annual volume of preservative treated (pressure treatment) wood was relatively at a stable level of approximately 500,000 m³. After the prominent peak of 709,000 m³ in 1968, 500,000 to 600,000 m³ of wood had been annually treated until 1980. In the 1980's the pace of production of preservative-treated wood gradually declined, down to 400,000 m³ in 1988. As for commodities treated with wood preservatives, poles and sleepers have been remarkably decreasing, and wood foundation sills which newly appeared on the market in the late 1960's became a major item. It is expected that new treated commodities will be accepted among Japanese people to stimulate the activity of wood preserving industry in Japan.