In fast-changing business environments, there are companies that have developed autonomous decentralized organizations for better adaptability and productivity. The company split-up and the line company system are typical methods for this, and are widely adapted in business communities. There are problems, however, on how to coordinate decentralized, autonomous divisions. Mayekawa Mfg. Co., Ltd, that has been acknowledged as a model case of autonomous decentralized organizations, started to try to unify the total Mayekawa Group three years ago. Based on their experiences, an investigation is made on why a change from decentralization to integration is needed, and on how it has been done. Through this study of Group Unification" of Mayekawa Mfg. Co., Ltd, six principles for integration of an autonomous decentralized organization would be revealed, namely, clear definition of business territories, total standardization of skills and knowledge, reinforcement of specialization, systematization of organic networks, mutual aids within the community, and sharing of perceptions of all members. These principles seem to be effective for autonomous decentralized organizations to improve productivity through better coordination within themselves, as well as superior adaptability to environmental changes. A comparison with Kyocera Corporation, another famous case of autonomous decentralization, would give us some more supporting evidences.