The present invention relates to [1] a process for producing a pigment water dispersion liquid of polymer particles containing an azomethine metal complex pigment (A), said process including the step of subjecting a mixture containing the azomethine metal complex pigment (A), an uncrosslinked aromatic group-containing polymer (b) and water to dispersion treatment using a medialess disperser at an accumulated input energy of not more than 5.0 kWh/kg, [2] a pigment water dispersion liquid containing an azomethine metal complex pigment (A) and a polymer dispersant (B), in which in an optical absorption spectrum of the pigment water dispersion liquid, a ratio of a maximum absorbance (A1max) in a wavelength range of not less than 440 nm and less than 465 nm to a maximum absorbance (A2max) in a wavelength range of not less than 420 nm and less than 440 nm [(A1max)/(A2max)] is not less than 1.000, and [3] a water-based ink for ink-jet printing, containing the aforementioned pigment water dispersion liquid.