A vehicle speed control system includes a road shape recognition unit which recognizes a road shape, a target speed setting unit which sets a target speed according to the road shape, a speed control unit which controls the host vehicle's speed according to the target speed, a parameter detecting unit which detects at least one of parameters representing the driver's steering rotation, a yaw rate of the host vehicle, and a lateral acceleration of the host vehicle, and a first acceleration determining unit which, after the speed control unit has decelerated, determines whether or not to accelerate the host vehicle according to reference parameters based on a road shape and the host vehicle's speed and parameters detected by the parameter detecting unit, wherein if the first acceleration determining unit has determined to accelerate, the target speed setting unit sets a target speed of the host vehicle according to a predetermined acceleration.