Chinese kiri woods (Paulownia spp.) are divided into 9 species and 4 variations. They are distributed in three areas in China Huang He (the Yellow River) area, Chang Jiang (Yangtze) area, and north-west dry area. Cultivation of kiri woods has been developed in 23 provinces. The amount of the accumulation is 200 million cubic meter and the amount of the log production is 2 million cubic meter per year in 1990. The trade between Japan and China started in 1896 and the total amount is 79 thousand cubic meter in 1990 mainly for furniture. The kiri woods are ring-porous or semi-ring-porous wood, and are very light to intercept the transmission of water, humidity, and heat.