A map information correction method for correcting map information of a map of an own vehicle including information of a lane boundary line (22L, 22R) used in driving assistance function to generate a travel trajectory based on the lane boundary information and to control the own vehicle to assist travel of the own vehicle along the generated travel trajectory, the method comprising: detecting a position with respect to the own vehicle of a lane boundary line (20L, 20R) set in place on a road surface around the own vehicle; estimating an own position on the map of the own vehicle; and calculating translational correction parameters, which are correction amounts by which boundary points of the lane boundary line (22L, 22R) of the map are corrected by translation, and rotational correction parameters, which are correction amounts by which boundary points of the lane boundary line (22L, 22R) of the map are corrected by rotation; wherein the rotation is a rotation about a rotation center set on the lane boundary line (22L, 22R) of the map; the method characterized by further comprising correcting, depending on the estimated own position and the detected position of the lane boundary line (20L, 20R), a position of the lane boundary line (22L, 22R) included in the map information by, in a first region, a larger rotational correction amount than in a second region and, in the second region, a larger translational correction amount than in the first region; wherein the first region is a region located ahead of the own vehicle and within a predetermined distance from a position of the own vehicle and the second region is a region located ahead of the own vehicle and farther than the predetermined distance from a position of the own vehicle; and each of the translation correction amounts and the rotational correction amounts minimize an error between corresponding points of the lane boundary line (23L, 23R), obtained after moving the lane boundary line (22L, 22R) of the map and the detected position of the lane boundary line (20L, 20R). detecting a position with respect to the own vehicle of a lane boundary line (20L, 20R) set in place on a road surface around the own vehicle; estimating an own position on the map of the own vehicle; and calculating translational correction parameters, which are correction amounts by which boundary points of the lane boundary line (22L, 22R) of the map are corrected by translation, and rotational correction parameters, which are correction amounts by which boundary points of the lane boundary line (22L, 22R) of the map are corrected by rotation; wherein the rotation is a rotation about a rotation center set on the lane boundary line (22L, 22R) of the map; the method characterized by further comprising correcting, depending on the estimated own position and the detected position of the lane boundary line (20L, 20R), a position of the lane boundary line (22L, 22R) included in the map information by, in a first region, a larger rotational correction amount than in a second region and, in the second region, a larger translational correction amount than in the first region; wherein the first region is a region located ahead of the own vehicle and within a predetermined distance from a position of the own vehicle and the second region is a region located ahead of the own vehicle and farther than the predetermined distance from a position of the own vehicle; and each of the translation correction amounts and the rotational correction amounts minimize an error between corresponding points of the lane boundary line (23L, 23R), obtained after moving the lane boundary line (22L, 22R) of the map and the detected position of the lane boundary line (20L, 20R).