. . "That is, an ethanol-based ink for marking pens of the present invention is characterized by comprising at least one dye selected from the group consisting of dyes represented by the following formulae (I) to (IX) and a dye of Color Index No. Solvent Black 7, an ethanol-soluble resin, and ethanol: ##STR1## (wherein R1 is --CH3 or --C2 H5, R2 is --H, --CH3, --Cl or --SO2 NH2, R3 is an alkyl group of" . . . .