Disclosed is a method of displaying a rear side obstacle of a vehicle, including: a first measuring step of measuring a first distance between a vehicle and an obstacle using a first sensor; a determining step of determining a position of the obstacle using the first distance, a moving distance of the vehicle, and a steering angle of the vehicle related with the moving distance; and a displaying step of displaying the position of the obstacle. Therefore, the position of the obstacle at the rear side of the vehicle is precisely predicted so that a driver may be notified in advance that the vehicle may hit the obstacle.