It is difficult to merge text document and to remake use of documents on the most collaborative document authoring system using text document, and also to provide the storage place for saving and keeping documents. It has vulnerable drawbacks about the security though it provides the accessible abilities due to basing it on Web. In this paper, we design and implementation the collaborative document authoring system for XML document to improve a couple of problems on these systems. For these, we based on the DOM to manipulate the modeling object documents and utilized RMI on this system without considering socket communication when it transmits and receives Java objects. We improved the security through processes of authentication. By providing templates and editing functions such as annotation, visualization of document structures, we made easier making collaborative document authoring more than ever.