To provide a drain gutter for leading rainwater penetrating through a road surface and a ground surface from an upper opening thereinto and draining the led rainwater therefrom, wherein the drain gutter hardly undergoes the accumulation of deposits therein or can easily remove the deposits accumulated therein little by little, to thereby ensure good draining performance.

The drain gutter has the interior thereof constricted at an intermediate location in a gutter depth direction to form a narrow water dropping port, and is composed of a taper portion formed above the constriction extending from an opening of the gutter to the water dropping port, and a water channel below the water dropping port. The width of the water dropping port is set to a narrow value that allows rainwater flowing into the drain gutter to be retained at the taper portion and that is sufficient for functioning as a nozzle when the retained rainwater drops from the water dropping port.