To provide a driving support system that does not executes unnecessary support control for a driver who fully recognizes that there is a possibility of a collision and performs a braking operation and that executes the support control at appropriate timing for a driver who does not perform the braking operation because of carelessness despite there is the possibility of a collision.

When a PCSECU 5 decides that there is a possibility of a collision of an own vehicle with an obstacle detected by a laser radar 3, a VSCECU 7 sequentially executes primary brake control that is avoidance support control for avoiding a collision, and secondary brake control that is collision prevention control for preventing a collision. After the VSCECU 7 executes the primary brake control, and before the VSC ECU 7 starts execution of the secondary brake control, when a brake pedal sensor 71 detects a driver's braking operation, the primary brake control is canceled.