It is a basic understanding of the current discussion on sustainable development that the high consumption level of non-renewable resources in industrial societies ought to be reduced in absolute figures and that the use of renewable resources should not go beyond the carrying capacities of ecological systems. It is evident that sustainable development will not be attained without regular (annual) information on dimension, structure and development of the physical exchanges between society and nature. National material balances therefore are to be regarded as one important requirement for achieving sustainable development. As a basic requirement of ecological restructuring of economies, the production and consumption of selected materials should be registered in an accounting form. Other material flow accounts describe the total material throughput of an economy. Austria, Germany and Japan were among the first countries to provide material flow accounting data for the whole economy. In Germany, material flow balances are already a firm part of integrated environmental and economic accounting. The physical accounting of material and substance flows on a regional and national scale is a rapidly growing field of current research on sustainability. Therefore the coordination of ongoing projects on an international level is an important prerequisite for providing a coherent framework of material and substance flow accounting methodology. Estimations for Austria show an average resource consumption of 29 tons per capita and year (1990). 83 percent of the yearly total material demand (water and air excluded) is taken from domestic resources, 17 percent is imported (materials, goods). About 10 percent of the domestic material throughput is exported. More than a third of total material throughput is turned back to nature in the form of emissions and waste. About one half of annual demand remains in the system and leads to a net increase in long-term stocks (above all in the form of buildings and infrastructure). The main cause for the high increase in the total material throughput of the Austrian economy over the last twenty years is the demand for construction materials. The value added per material or energy throughput unit, the total resource productivity, has increased by about 30 percent during that period. Nevertheless, absolute figures for resource consumption increased by approximately the same amount.