Navigation service based on webGIS has a fast development. But recent research is only based on the outdoor environment or the indoor environment respectively. There is not a way to integrate them together. To cope with this problem, the paper describes an approach to integrate indoor map and outdoor map together using Google map APIs and discuses the navigation service based on the integrated map. A library book navigation system is implemented as an example. The navigation application will run on users' intelligent mobile device and the device's location can be got through GPS or Wi-Fi. Compared with current book searching system, it is time saving for users find the book, for the book's querying results will show on the map. A route from the users' location to the book' location will be calculated and shown on the map to help users find the book more quickly.