Disclosed is a cruise control method including traveling a vehicle at a speed input by a driver, receiving road information from a navigation device, confirming whether or not deceleration information is present in the road information, confirming a speed corresponding to the deceleration information if the deceleration information is present, and controlling a speed of the vehicle to the confirmed speed if the confirmed speed is greater than the input speed. If the vehicle speed exceeds the speed limit of a road, the vehicle speed is automatically reduced to below the speed limit, and a warning operation is performed. Thereby, probability of accidents due to speeding may be reduced, and it may be possible to make the driver obey the Road Traffic Act and to prevent imposition of fines due to speeding. Further, the vehicle speed is automatically reduced at bumps or curves, resulting in enhanced safety and driver convenience.