In a cruise control system for a vehicle, a cruise ECU calculates a cornering resistance applied to the vehicle based upon a steering angle, when a vehicle turns. The cruise ECU calculates a speed reduction amount as a correction vehicle speed based upon the cornering resistance. The cruise ECU subtracts the correction vehicle speed from a set vehicle speed to set a target vehicle speed so that the vehicle speed becomes lower as the cornering resistance is larger. The cruise ECU controls the vehicle speed to be within a permissible speed range of the target vehicle speed.