An aqueous marking ink composition is provided, wherein it has a suitable and good wetting property to a non-absorbing surface of metals, resins and the like stained with oils such as a cutting oil and lubricant, and it can write smoothly thereon at a low viscosity without being repelled to make it possible to obtain drawn lines having a high masking property and a high fixing property; further, it is readily redispersed by a simple stirring operation even when a masking agent settles down after the passage of time, and it is excellent in a masking property and stability; and in particular, it can readily be stirred by using even a stirring member having a small specific gravity. The aqueous marking ink composition is provided with such a constitution that it contains at least 1 to 20 % by mass of a resin which is water-soluble and has a hydrophobic part in a molecule thereof, a colorant containing at least 5 to 30 % by mass of titanium oxide, 0.05 to 2 % by mass of at least one selected from acetylene glycols, acetylene alcohols or derivatives thereof, 1 to 20 % by mass of a water-soluble solvent having a vapor pressure of 5 mmHg or less at 25°C and water.