To obtain a hygroscopic fiber structure simultaneously satisfying both excellent hygroscopicity and high color fastness by dyeing a fiber structure containing a specific hygroscopic resin with a treating liquid containing a dyestuff and an inorganic salt.

This method for producing a hygroscopic fiber structure having good color fastness comprises dyeing a fiber structure comprising polyester fibers and/or polyamide fibers and containing 5-35 wt.% of a hygroscopic resin having a moisture absorption coefficient different of ≥10%, such as a blocked polyetherester, in a treating liquid containing a prescribed amount of the dyestuff and at least one kind of inorganic salt selected from the group consisting of sodium sulfate, potassium chloride, ammonium sulfate and ammonium chloride in a 3 wt.% concentration.