Provided is a vehicle periphery monitoring system that facilitates a driver's understanding about a photographing direction of an object which appears in an overlapping area of a bird's-eye view image generated from multiple photographed images. A displaying bird's-eye view image is generated by combining bird's-eye view image segments generated from the multiple photographed images photographed in a partially overlapping manner with superimposing mutually overlapped areas thereof. In displaying the displaying bird's-eye view image, a boundary-added bird's-eye view image formed by adding a boundary indicator to the overlapping area of the bird's-eye view image is displayed on a display unit; then, a merged superimposed image is displayed. The merged superimposed image is obtained by merging the overlapped areas of the bird's-eye view image according to a preset merger relationship.