Our group is developing the NIMS Materials Database (MatNavi) and MI²I data platform contents as well as in charge of building, operating, and managing systems. We are developing WebAPI for seven databases which NIMS has already own, including the databases of inorganic materials, polymers and metal structual metals. We also provide intranet servcies and explore methods and technologies for collecting, processing, managing and providing new data to build materials big data. In addition, we intend to publish the data obtained at MI²I, data analysis tools developed by MI²I as well as machine learning and simulation software, on this platform.