To provide a replacing construction method of a protective fence for an existing bridge capable of performing replacing work of the protective fence without breaking down existing ground covering concrete.

This invention has a process of removing the protective fence 1 for the existing bridge by cutting a column 3 exposed from the ground covering concrete 2, a process of filling a remaining hole 6 left as it is in the ground covering concrete 2 by mortar 12, a process of inserting and fixing an anchor bolt 10 by a hardener by boring an anchor bolt installation hole 7 around the remaining hole 6, and a process of installing the protective fence for the bridge by fastening and fixing a new column 3A to the anchor bolt 10.