A road path searching apparatus applicable to a car navigation system is disclosed. Road map data with different level of detail for defining a predetermined area is stored previously in a memory device. First, nodes Nai and Nbj adjacent to each of the search nodes Pa and PB are detected based on map data having a high level of detail. When nodes Nai and Nbj exist on a map of a lower level of detail, a map of one lower level of detail is selected as a map to be used in the searching process. Accordingly, as following searching process is performed based on the map data of lower level of detail, required processing time is reduced.