This paper introduces an automatic method of extracting accessible information from CityGMLLoD4 files. The proposed solution could generate accessible rectangles from supplied files, and then use these rectangles and their spatial relationships to produce their intersection partsand nodes. Thus, we can use these accessible objects to meet the path finding demand of navigation and evacuation simulation. Furthermore, the stored accessible navigation rectangles could be utilized to meet dynamic routing demand, whichcould affect the navigation environment, in the future work.