An autonomous driving system having an autonomous driving assistance apparatus includes: a gateway unit wirelessly communicating with a router among a plurality of routers installed in an autonomous driving road; a signal processing unit providing identification information of a vehicle at the time of setting a wireless communication link with each router and providing driving path information of the vehicle to the router every set cycle; a path tracking unit determining a speed, a progress direction, and a steering angle of the vehicle included in the driving path information so as to drive the vehicle based on driving path information; a speed control unit controlling a speed of the vehicle based on the speed determined by the path tracking unit; and a steering angle control unit controlling a steering angle of the vehicle based on the progress direction and steering angle determined by the path tracking unit.