To provide a charge controlling agent having negative electrification imparting properties on a practical use level, and usable to a color toner in colorless or in a light color, in which an electrostatic charge by electrification of resin powder in a toner or the like is stable to an environmental change, and having excellent storage stability and durability and high safety; to provide a charge controlling method for resin powder using the charge controlling agent, and to provide a toner.

The charge controlling agent is composed of the diamide body of naphthalene dicarboxylic acid as an effective component. Also, a charge controlling method for a resin powder and a toner use the charge controlling agent.