A slip detection system for a vehicle comprises an engine speed detector configured to detect an engine speed of an engine mounted in the vehicle, an engine speed increase rate detector configured to detect an increase rate in a predetermined time of the engine speed detected by the engine speed detector, and a slip determiner configured to integrate values of increase rates in respective predetermined times, from when the increase rate detected by the engine speed increase rate detector becomes larger than a first threshold until the increase rate becomes smaller than the first threshold, and to determine that a drive wheel of the vehicle is in a slip-state when an integrated value resulting from integration of the values of the increase rates becomes larger than a second threshold.