To provide a process for producing an alkyl-etherified cellulose that makes it possible to produce the alkyl etherified cellulose having a high substitution degree with a relatively small amount of a by-produced salt and to recover a dissolving agent and reutilize it.

The process for producing an alkyl-etherified cellulose comprises subjecting a hydroxy group (a) of a cellulose (A) to alkylation reaction in an ionic liquid (B) using a dialkyl carbonate (C) wherein a cation constituting the ionic liquid is preferably one or more kinds of cations selected from the group consisting of imidazolium cations; the substitution degree of alkyl groups of the alkyl etherified cellulose produced in the production process is 2.1-2.9; and the content of a neutralized salt of an alkali metal is not more than 100 ppm.