Provided is a method to produce resin particles having a uniform particle size by a suspension polymerization method, and to provide a method for simply producing resin particles having high dispersibility into an organic binder or an organic solvent, wherein a resin particle assemblage comprises a resin particle assemblage in which an ester moiety constituting a sorbitan fatty acid ester having no polyoxyalkylene group is buried in the resin particles, and a large number of sorbitan moieties bonded with the ester moiety exist on a surface of resin particles, and a coefficient of variation (CV value) of a mean particle diameter of the resin particles forming the resin particle assemblage is in the range of 30% or less.