To provide a charge controlling agent for electrophotography, which presents sufficient triboelectric chargeability to a toner, is useful particularly for a color toner and further for a polymerized toner, increases a charge rising rate, has a high electric charge amount, is excellent in charging characteristics, stability over time and environmental stability and yet is safe without posing any problem regarding waste regulations, and a negatively chargeable toner for developing an electrostatic image, which uses such a charge controlling agent and which has a high charging performance. A charge controlling agent comprising, as an effective component, at least one type of cyclic phenol sulfide represented by the following formula (1), and a toner comprising such a charge controlling agent: