To provide a method for producing amide-modified carboxymethylcellulose by which amide-modified carboxymethylcellulose can be obtained by a simple process in a high yield and an ionic liquid which is a reaction solvent can be recovered at a high recovery rate and reused.

The economical method for producing amide-modified carboxymethylcellulose comprises: a reaction step of amide-modified carboxymethylcellulose including a step of adding an amidating agent to a cellulose solution or dispersion (A) comprising carboxymethylcellulose and an ionic liquid to bring the carboxymethylcellulose into an amidation reaction; and an aftertreatment step in which, after the reaction step, an organic solvent is added to precipitate amide-modified carboxymethylcellulose, this product is separated, and the ionic liquid is recovered and reused.