© 2020 and published by the Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), Hong Kong. This paper introduces ideas to use Mixed Reality (MR) technologies in craftsman's work of architecture.One of the backgrounds of this study is emerging technology of Mixed Reality becoming much easier to use recently with new devices such as Microsoft Hololens. Among many possible applications of this technique in architectural work, we particularly choose Japanese traditional timber joinery 'Kumiki' as a model case of complicated architectural work.We found that people need a certain sense of 3D recognition and knowledge about right order of assemble. That is what we can suggest for users with our MR guidance system named 'Holonavi' which can show appropriate information in 3D vision in real time. The aim of our research is to find useful knowledge about effective ways and sufficient information to guide users. As a conclusion, we found that guidance with MR technology gives users to have a recognition more effectively for take of right action when they are moving their viewpoint around the object and when they located in the range of reachable distance to the objects. It is the first achievement for use of 'Holonavi' to let people feel more fun to craft something by their hands aided by computer.