To provide an expandable connecting structure of eaves gutters having simple constitution, easy in manufacturing an expansion joint, and easy in construction.

This expandable connecting structure of the eaves gutter has the two eaves gutters 1 and 1 positioned in the lengthwise direction so that mutual end parts are opposed, cut-off walls 10 and 10 fixed between the respective end parts of the eaves gutters, and opposed at a prescribed interval, and an expandable cover 15 positioned on the outer peripheral side of the eaves gutters and the cut-off walls, and connected so as to block up an interval by straddling the respective end parts. The cut-off walls 10 have an outer peripheral rib 12 as a projecting part projecting from an outer peripheral surface of the eaves gutters 1. The expandable cover 15 has folding-back parts 16a, 17a, and 18a folded back to the outer peripheral surface side of the eaves gutters. The outer peripheral rib and the folding-back parts are opposed.