To provide a backfilling method, and a backfilling material for reducing a civil engineering waste material, effectively using a waste roof tile, improving the environmental problem for inexpensively backfilllng, and reusing resources by enabling backfilling by manufacturing the backfilling material at a job site by dug-up sediment and a roof tile crushed material for forming a burying hole.

This backfilling method comprises a backfilling material manufacturing process of manufacturing the backfilling material near a digging-up place by mixing the sediment dug up for forming the burying hole and the roof tile crushed material of crushing the waste roof tile by a crusher into the ground surface of a part for burying a pipe so that the maximum particlesize is 100 mm or less, a 4760μ sieve passing quantity becomes 25 to 100 %, a 74μm sieve passing quantity becomes 0 to 25 %, and a plasticity index on a 420μm sieve passing quantity becomes 10 or less, and a backfilling material input process of inputting and backfilling the backfilling material manufactured by this backfilling material manufacturing process after arranging the pipe in the burying hole.