To provide a navigation system capable of acquiring the optimum path and the optimum arrival time of a train by specifying the train with a user being onboard based on information of the present position of the user.

The navigation system comprises a user position grasping means for grasping the present position of the user onboard the train based on GPS information from a first terminal carried by the user, a train position grasping means for grasping the present position of a second terminal based on GPS information from the second terminal mounted on the train, and an operational situation grasping means which acquires the operational situation of the train from the outside and stores and controls it in a file. The train with the user being onboard now is specified from the present position of the first terminal grasped by the user position grasping means and the present position of the second terminal grasped by the train position grasping means, and the path and the required time to a target station are automatically calculated based on the latest information on the train acquired by the operational situation grasping means.