A curve modeling device includes a curvature calculation unit, a curvature correction unit, and a node information generation unit. The curvature calculation unit calculates a curvature of each sampling point on a route based on location information of each sampling point. The curvature correction unit corrects the curvature at each sampling point and approximates the route by a straight line interval, an arc interval, or a smooth curve interval. The node information generation unit builds a shape model of a curve included in the route by generating node information indicative of a node location on a road corresponding to the route based on the corrected curvature of the sampling point. The curvature correction unit corrects the curvature under a condition that an orientation difference defined by the calculated curvatures maintains a constant value.