Slip suppression control system for vehicle

A slip suppression control system for a vehicle includes a monitored value detecting device (33) for detecting a monitored value corresponding to a difference between a rotational speed of a front wheel and a rotational speed of a rear wheel of the vehicle, a threshold determiner unit (45) configured to determine a relationship between the monitored value detected by the monitored value detecting device and a threshold; and a controller (47) configured to initiate traction control for reducing a driving power of a drive wheel when the threshold determiner unit determines that the monitored value exceeds a predetermined start threshold, wherein the threshold determiner unit is configured to count a return time which lapses from when the monitored value exceeds the start threshold until the monitored value becomes smaller than second threshold; and wherein the controller is configured to determine whether or not to terminate the traction control based on the return time.