To better facilitate health information dissemination, using flexible ways to represent, query and visualize health data becomes increasingly important. Semantic Web technologies, which provide a common framework by allowing data to be shared and reused between applications, can be applied to the management of health data. Linked open data - a new semantic web standard to publish and link heterogeneous data- allows not only human, but also machine to browse data. Through a use case of WHO data, we develop a linked data based health information representation, querying and visualization system. Through out the book, we discussed how to develop such systems using RDF and triple stores, how to write codes for visualization and retrieval. For users who are not familiar with SPARQL queries, we show how to develop and use a search engine interface. From this work we can depict that current linked open data technologies have a big potential to represent heterogeneous health data in a flexible and reusable manner. By reading this book, you will be able to understand the new data storage and programming technologies in linked data based information system developments. Enjoy Reading