An abutment installing structure of a road bridge is provided to prevent an approach slab from being cracked at a border between the ground surface and the bridge by installing first and second auxiliary slabs in multiple layers on an abutment through anchors and to thereby prevent the abutment border from being bent. An abutment installing structure of a road bridge comprises an abutment(54) installed on both ends of the bridge to support the bridge upper board and formed with a first hanging unit and a second hanging unit to be faced with each other; an approach slab hung on the second hanging unit at one end and supported on the ground surface at the other end to support the road of the bridge border portion; auxiliary slabs(1,2) disposed on the lower surface of the approach slab, arranged in multiple steps, and buried under the ground as a panel to prevent soil on the lower side of the approach slab from sinking down; and a fixing means for fixing the auxiliary slabs on the abutment. The fixing means is composed of plural anchor holes(3) formed on the lateral side of the approach slab of the abutment and arranged in two steps; a screw pipe inserted into the anchor hole to be expanded and fixed by inserting a screw; an anchor(7) inserted into the screw pipe and formed with a screw thread(5) on one end and a fitting unit bent upward on the other end; and plural fitting holes formed at one side of the first and second auxiliary slabs to insert and fix the fitting unit of the anchor.
