1. A vehicle periphery monitoring system comprising: an obstacle detecting unit for detecting the presence of an obstacle in a periphery of a vehicle; an indicating unit for indicating the presence of an obstacle; a control unit for controlling said indicating unit to indicate the presence of an obstacle when the presence of the obstacle is detected by said obstacle detecting unit; and an imaging unit for capturing an image of the periphery of the vehicle; wherein if the detected distance from the vehicle to the obstacle detected by said obstacle detecting unit is equal to or greater than a preset distance, said control unit performs an image processing process on a viewpoint-changed image which is produced by changing the viewpoint of the image captured by said imaging unit, for thereby acquiring the height of the detected obstacle, and controls said indicating unit to either indicate the detected obstacle as a safe obstacle or inhibit the detected obstacle from being indicated if the acquired height of the detected obstacle is less than a preset height, and controls said indicating unit to indicate the detected obstacle as a dangerous obstacle if the acquired height of the detected obstacle is equal to or greater than said preset height.