To provide a clamping fitting for grating capable of facilitating the fixation work and obtaining stable fixing force.

This clamping fitting for grating consists of a hook member 10 having a hook part 11 engageable with an aggregate 81, a U-shaped member 2 having a U-shaped cross section, and a tightening bolt 3. A through hole 15 is provided in the hook member 10, and a screw hole 25 is provided in the U-shaped member 2. In a condition in which the aggregate 81 is engaged with the hook part 11 and a rack part 71 is inserted and arranged between the U-shaped member 2 and it, the tightening bolt 3 is screw-fitted in the screw hole 25 through the through hole 15 and is screwed in to hold the aggregate 81 between the hook part 11 and the rack part 71 and hold the rack part 71 between the tightening bolt 3 and a bottom plate part 22.