A water-based pigment dispersion comprising a polymer dispersant and a pigment, the polymer dispersant being prepared by crosslinking a carboxy group-containing water-insoluble polymer with a water-insoluble polyfunctional epoxy compound, in which carboxy groups of the water-insoluble polymer are at least partially neutralized by an alkali metal compound, and an acid value, a neutralization degree and a crosslinking degree of the neutralized water-insoluble polymer satisfy the following conditions 1 to 3: Condition 1: a value calculated according to the formula: 100 − neutralization degree − crosslinking degree / 100 × acid value of water − insoluble polymer A, is not less than -30 mgKOH/g and not more than 30 mgKOH/g; Condition 2: a value calculated according to the formula: neutralization degree / 100 × acid value of water − insoluble polymer A, is not less than 80 mgKOH/g and not more than 180 mgKOH/g; and Condition 3: a value calculated according to the formula: crosslinking degree / 100 × acid value of water − insoluble polymer A, is not less than 80 mgKOH/g and not more than 180 mgKOH/g, wherein the neutralization degree means a percent ratio (mol%) of a mole equivalent number of the alkali metal compound to a mole equivalent number of the carboxy groups of the water-insoluble polymer [(mole equivalent number of alkali metal compound)/(mole equivalent number of carboxy groups of water-insoluble polymer)], and the crosslinking degree means a percent ratio (mol%) of a mole equivalent number of epoxy groups of the water-insoluble polyfunctional epoxy compound to a mole equivalent number of the carboxy groups of the water-insoluble polymer [(mole equivalent number of epoxy groups of water-insoluble polyfunctional epoxy compound)/(mole equivalent number of carboxy groups of water-insoluble polymer)], wherein the water-insoluble polymer is vinyl-based polymers obtained by addition-polymerizing at least one vinyl monomer selected from the group consisting of a vinyl compound, a vinylidene compound and a vinylene compound, the number-average molecular weight of the water-insoluble polymer is not less than 2,000 and not more than 18,000 determined as indicated in the description, and the acid value of the water-insoluble polymer is not less than 200 mgKOH/g and not more than 320 mgKOH/g. Condition 1: a value calculated according to the formula: 100 − neutralization degree − crosslinking degree / 100 × acid value of water − insoluble polymer A, is not less than -30 mgKOH/g and not more than 30 mgKOH/g; Condition 2: a value calculated according to the formula: neutralization degree / 100 × acid value of water − insoluble polymer A, is not less than 80 mgKOH/g and not more than 180 mgKOH/g; and Condition 3: a value calculated according to the formula: crosslinking degree / 100 × acid value of water − insoluble polymer A, is not less than 80 mgKOH/g and not more than 180 mgKOH/g, wherein the neutralization degree means a percent ratio (mol%) of a mole equivalent number of the alkali metal compound to a mole equivalent number of the carboxy groups of the water-insoluble polymer [(mole equivalent number of alkali metal compound)/(mole equivalent number of carboxy groups of water-insoluble polymer)], and the crosslinking degree means a percent ratio (mol%) of a mole equivalent number of epoxy groups of the water-insoluble polyfunctional epoxy compound to a mole equivalent number of the carboxy groups of the water-insoluble polymer [(mole equivalent number of epoxy groups of water-insoluble polyfunctional epoxy compound)/(mole equivalent number of carboxy groups of water-insoluble polymer)], wherein the water-insoluble polymer is vinyl-based polymers obtained by addition-polymerizing at least one vinyl monomer selected from the group consisting of a vinyl compound, a vinylidene compound and a vinylene compound, the number-average molecular weight of the water-insoluble polymer is not less than 2,000 and not more than 18,000 determined as indicated in the description, and the acid value of the water-insoluble polymer is not less than 200 mgKOH/g and not more than 320 mgKOH/g. wherein the water-insoluble polymer is vinyl-based polymers obtained by addition-polymerizing at least one vinyl monomer selected from the group consisting of a vinyl compound, a vinylidene compound and a vinylene compound, the number-average molecular weight of the water-insoluble polymer is not less than 2,000 and not more than 18,000 determined as indicated in the description, and the acid value of the water-insoluble polymer is not less than 200 mgKOH/g and not more than 320 mgKOH/g.