Based on the recent statistical data available in the literature, detailed survey on the virgin biomass resources and their residual (unused and wasted) portions was made in their quantities and available masses. In addition, a biomass flow in Japan was proposed. Total quantity produced and available mass were estimated to be about 360 and 76Mt, respectively, in Japan in 1999. The latter value is equivalent to 125 Mt of carbon dioxide. This is an enormous quantity, which corresponds to about 11% of the carbon dioxide emitted in 1990 in Japan. The result shows that a large amount of biomass resources, which is a sufficient quantity for the target of the 6% reduction for carbon dioxide emission ratified in the Kyoto Protocol of the Third Conference of the Parties (COP3), are disposed without using effectively. (c) 2005 Elsevier Ltd. All rights reserved.