Bioenergy is expected to become one of the key energy resources to cope with global warming and exhaustion of fossil fuel resources. Biomass is renewable and free from net CO2 emissions as long as it is maintained sustainably. There are several studies concerning bioenergy potential, but they are hardly comparable because of the complexity of the assumed parameters, which relate to food, timber and paper supply, forest management, etc. In this study, bioenergy (expressed in Joules) is divided into plantation bioenergy produced on land and bioenergy recovered from biomass residues in the processes of harvest, conversion and consumption for food, timber and paper. We propose a "Biomass Balance Table", which shows systematically the flows of various biomass forms. The scheme of a Biomass-Balance Table is similar to that of an energy-balance table. The steps of the biomass processing (i.e. harvesting, conversion and consumption) are expressed in the column, and biomass forms are expressed in the row. Tables have been constructed for 10 regions in the world in 1990. The world has an existing energy potential from biomass residues of 88 EJ (i.e. 26% of 335 EJ of primary energy supply in 1990) and Japan has 2.02 EJ (10% of 19.52 EJ of primary energy supply in 1990). North America, the former USSR and eastern Europe, and Western Europe have large potentials of wood biomass residues and other Asian countries and the centrally-planned economies of Asia have large potentials food biomass residues.