Charge control agent whose active ingredient is a zinc compound of an alkylsalicylic acid derivative, the compound being a zincified alkylsalicylic acid derivative which is an alkylphenol derivative having a carboxyl group introduced thereto; Toner for developing electrostatic images, comprising said charge control agent, a coloring agent and a binder resin for toner; Charge control resin particles comprising solidified milled particles of a thermally kneaded mixture of at least said charge control agent and a resin.