Disclosed are hollow polymer particles composed of a crosslinked polymer having a comparatively small particle diameter and a narrow particle diameter distribution, an aqueous dispersion of the particles, and an ink having good flying property.The hollow polymer particles are obtained by emulsion-polymerizing a crosslinkable polymerizable monomer composition absorbed in seed particles and containing a crosslinkable monomer component and a hydrophilic monomer component, wherein the seed particles are particles of a polymer having a weight average molecular weight of 500 to 15,000, and obtained by emulsion-polymerizing 100 parts by mass of a non-crosslinkable polymerizable monomer in the presence of 0.01 to 5 parts by mass of a chain transfer agent composed of at least one compound selected from the group consisting of .alpha.-methylstyrene dimer, thiuram disulfides and terpene hydrocarbons. The ink contains the hollow polymer particles.
