This topic is closely related to the problem of the "unipolar concentration on Tôkyô" (Tôkyô ikkyoku shûchû), i.e. the domination of the Tôkyô Metropolitan Region not just in population or manufacturing distribution but in the geography of the service sector of the Japanese economy, particularly of financial and producer services. Are there limits of urban growth in a global city like Tôkyô ? The author's hypothesis on the problem "agglomeration economies" vs. "agglomera-tion diseconomies" is like follows: Although the agglomeration advantages in the Tôkyô Metropolitan Area seem to be overused (from the Western point of view) and are supposed to be at a point of depreciating through an increasing amount of agglomeration disadvantages, they will continue, though not as dramatic as before, also in the future. The hypothesis is based on the following considerations: 1. Tôkyô?s metropolitan stability, efficiency and quality of life, 2. Japanese "mental maps", values and behaviour, 3. making full use of what is technically possible for the sake of strengthening the agglomeration economies, 4. the "unipolar concentration on Tôkyô" as a problem of political decision-making: a laissez-faire phenomenon or possibly a result of politcal priority - made for what purpose ? by whom ? With regard to the theory of agglomeration this paper shows that neoclassical concepts are not convincing, and that "regional factors" must not be neclected. Due to the complexity of the topic interdisciplinary research is regarded to be necessary in areas such as economics, business management, politics, sociology, human geography, psychology, architecture and engineering, culture and history.