To provide a ditch cover having no backlash by its shrinkage in winter or its deviation due to the transit of vehicles or when auxiliary ditch covers are separated from the hook pieces of a receiving frame in particular and capable of complementing the gaps generated by the shrinkage or deviation when the ditch cover is longitudinally connected.

This ditch cover is constituted of main ditch covers 1, 1... having an isosceles triangle shape and used for a U-shaped ditch block and auxiliary ditch covers 2, 3 obtained when the main ditch cover 1 is bisected into the right and left and having a right triangle shape. The outside faces of the leg pieces 4', 7; 4", 7' on the outside of the auxiliary ditch covers 2, 3 are matched with the outside faces of cover boards, and notches 8 are provided at a part of them to be coupled with the hook pieces of a receiving frame. Slender and rectangular bolt holes 10 are provided on the ribs 9 suspended on the back face of the cover board between the leg pieces 4', 7; 4", 7' of the auxiliary ditch covers 2, 3, and the auxiliary ditch covers 2, 3 provided with the bolt holes 10 on the ribs 9 suspended on the back face of the cover boards between the leg pieces.