Carbon black is the most widely used pigment for black electrophotographic toners. In this article the effects of carbon black on tribocharaging of two-component developers reported in the published literature are reviewed and compared to experemental work done recently. Carbon black is found to have the following effects on the triboelectric properties of model toners made from carbon black in a polymer binder: (1) In toners compared at the same carbon black loading, toners containing carbon blacks with greater work function (or surface acidity) charge more negatively. (2) Increasing the carbon black content causes the absolute value of the charge-to-mass of model toners to decrease when the toner is charged either positively or negatively using poly(methylmethacrylate) coated carrier or poly(vinylidine fluoride) coated carrier. (3) Q/m when the toner is charged negatively is a linear function of Q/m when the same toner is charged positively. (4) Increasing the carbon black content causes the absolute value of the slope and the intercept of linear plots of mass-to-charge as a function of the mass ratio of toner to carrier to increase. A steady-state version of the surface state model of tribocharging is developed and compared to experimentally observed tribocharging behavior. In this model, the rate of charging of the toner and the rate of discharging of the toner due to increased conductivity related to the carbon content of the toner are assumed to be equal at steady state. The model predicts all four of the observed behaviors.