This study presents the method of GIS application for the characteristic feature of the national road`s transportation network, traffic volume and shortest path transportation navigation of the Metropolitan Seoul in 1992 and 1999. The topological character of the transportation network is examined in terms of the GIS soft program, Arc View / Arc Info. Shortest path finding is one of the basic functions provided in the network analysis of the GIS. A network in GIS consist of the set of nodes and the set of links. A positive number called maximum traffic volume and real distance is assigned to each link. There are many examples for geographic networks such as streets, highways, railroad, pipelines, electric lines, cable lines and the like. A GIS network analysis system analyzes and models geographic networks and enables users to solve a variety of problems concerning geographic networks such as finding a optimal transportation route. In path finding there are two types of vehicle routing problems. One is to find a shortest route between two nodes. The other is to find an optimum route among many points, which is known as the traveling salesman problem. In this thesis, we also present a method for solving a multiple route among many points in a network. The first step in this method assigns nodes and traffic volume to nodes. The methods above have been implemented on the Gothic GIS system. And we have implemented our GIS network analysis system for path finding, the implemented system consist of the optimal path finder. The system in this thesis also solves vehicles routing problems efficiently in GIS networks. According to the analysis, three view point were considered. First, the traffic volume was measured in terms of its national road network. Second, the transportation facilities(private car, bus, truck) and shortest pathway navigation was examined on the basis of the each transportation network traffic flow volume. Last, the correlation between the formation of a region and the traffic volume was investigated. Rank-size order of traffic flow volume in Seoul, Metropolitan cities have much to do with such variables as population, local tax, number of employment, volume of waste, parking space, and wholesaling. The Metropolitan Seoul can be divided into 8 major transportation axies for example, Seoul-Inchon, Seoul-Ganghwa, Seoul-Munsan, Seoul-Yonchon, Seoul-Gapyung Seoul-Yeoju, Seoul-Pyungtac, Seoul-Anjung. Traffic volume is highest in Seoul and relatively higher in nodes surrounding Seoul. However in nodes on the far suburb such as Munsan, Anjung, Paengsung, Anjung, Yonchon`s transportation axies traffic flow volume is low. The traffic volume was closely related to the city`s economic scale.