A medical information management system (MIMS) is developed using the semantic Web technologies for medical data management in the development of a diagnosis method of dementia. This system manages metadata that are extracted from the medical data files automatically or are created by researchers. One of the characteristics of the data set of MIMS is that some of the data items are changed occasionally by the progress of the research. For supporting such change of the data items, MIMS provides three mechanisms. (1) A pluggable metadata extractor is a metadata extraction mechanism that given as a plug-in which automatically generates a set of metadata from medical data files. (2) An RDFView is a semantic Web retrieval mechanism which provides Web application programming interfaces created from SPARQL templates dynamically. (3) A representation mechanism is a method to display a result of the semantic Web retrieval service.