A cruise control system includes a curve state detecting section, a target deceleration rate calculating section, a deceleration control section, a map matching detecting section, a position evaluating section and a revising section. The deceleration control section is configured to execute deceleration control within a deceleration control region before a curve existing in front of the vehicle. The map matching detecting section is configured to detect whether a map matching operation caused a vehicle traveling position to move onto a traveling road. The revising section is configured to perform at least one of increasing a deceleration rate of the vehicle and extending an end position of a deceleration control region to a position inside the curve based on a positional relationship between the vehicle traveling position and the curve when the vehicle traveling position after the map matching operation is within the deceleration control region.