A position registering apparatus includes an acquiring unit that acquires traveling state information concerning a mobile object; a position identifying unit that identifies a current position of the mobile object based on the traveling state information and map information; a parking determining unit that determines whether the mobile object is parked when the current position is identified not be on a road; and a registering unit that registers a point of deviation from the road by the mobile object as an entrance point to a parking lot when the current position that has been identified to be on the road is identified to be not on the road and the mobile object is determined to be parked. The registering unit further registers the current position identified upon the parking determining unit determining that the mobile object is parked, as a parking lot position correlated with the entrance point.