A cruise control system includes a speed sensor, an instructor, an accelerator sensor and a speed controller. The speed sensor detects a host vehicle speed. The instructor indicates a start of a cruise control operation. The accelerator sensor detects an operational position of an accelerator pedal at the start of the cruise control operation and a signal position of the accelerator pedal subsequent to the start of the cruise control operation. The speed controller terminates the accelerator pedal from directly controlling an engine output after the start of the cruise control operation and memorizes the operational position of the accelerator pedal. The speed controller also changes the engine output according to a difference between the operational position and the signal position of the accelerator pedal.