A two-component developer for electrophotography includes a toner comprising toner particles and an external additive composed of a compound of imidazole series or an imidazole derivative. The external additive has a volume median particle size below that of the toner particles, or of 0.1 to 100 .mu.m. The amount of external additive is 0.001 to 5% by weight based on the weight of the toner particles. As a result, scattering of toner may be prevented and the formation of fog in the background may be reduced. In addition, the electrostatic charge characteristics of the toner may be improved and the electrostatic charge rises in a satisfactory manner.