A vehicle motion control system, comprising: a curve shape acquisition section for acquiring a curve shape ahead of an own vehicle; an own vehicle position acquisition section for acquiring a position of the own vehicle; and a vehicle motion control calculation section for calculating a command value of a longitudinal acceleration generated for the vehicle based on the curve shape and the position of the own vehicle; wherein with respect to the longitudinal acceleration command value having a travelling direction of the own vehicle as a positive value, the vehicle motion control calculation section calculates a negative longitudinal acceleration command value during travel of the own vehicle from before a curve to a point where a curve curvature becomes constant or maximum after the vehicle enters into the curve, and the longitudinal acceleration command value is changed based on at least one out of: an estimate of a maximum lateral acceleration which is calculated in advance by the vehicle motion control calculation section and which is presumably generated at a time of traveling a curve ahead of the own vehicle; a grade of a road ahead of the own vehicle; pedal operation by a driver; and a turning direction; characterized in that based on a temporal change of the curve curvature at a position away for a preset distance from the position of the own vehicle with the position of the own vehicle as an origin or away for a distance obtained from a product of a vehicle speed and a preset time, the vehicle motion control calculation section produces a decrease of the longitudinal acceleration command value which generates change in a longitudinal jerk that is a temporal change of the longitudinal acceleration. a curve shape acquisition section for acquiring a curve shape ahead of an own vehicle; an own vehicle position acquisition section for acquiring a position of the own vehicle; and a vehicle motion control calculation section for calculating a command value of a longitudinal acceleration generated for the vehicle based on the curve shape and the position of the own vehicle; wherein with respect to the longitudinal acceleration command value having a travelling direction of the own vehicle as a positive value, the vehicle motion control calculation section calculates a negative longitudinal acceleration command value during travel of the own vehicle from before a curve to a point where a curve curvature becomes constant or maximum after the vehicle enters into the curve, and the longitudinal acceleration command value is changed based on at least one out of: an estimate of a maximum lateral acceleration which is calculated in advance by the vehicle motion control calculation section and which is presumably generated at a time of traveling a curve ahead of the own vehicle; a grade of a road ahead of the own vehicle; pedal operation by a driver; and a turning direction; characterized in that based on a temporal change of the curve curvature at a position away for a preset distance from the position of the own vehicle with the position of the own vehicle as an origin or away for a distance obtained from a product of a vehicle speed and a preset time, the vehicle motion control calculation section produces a decrease of the longitudinal acceleration command value which generates change in a longitudinal jerk that is a temporal change of the longitudinal acceleration.