PURPOSE: To provide a water base dye ink prevented from discoloring with time.

CONSTITUTION: A water base dye ink containing a dye as a colorant (desirably one containing triphenylmethane) and further containing an inorganic reducing agent such as sodium bisulfite, ammonium sulfite, sodium hydrogensulfite, sodium sulfide or sodium thiosulfate. It is an ink in which the contained substances are prevented from being oxidized and which is prevented from being discolored.