EN
The individual Co site contributions to the magnetocrystalline anisotropy in RCo_{5}, RCo_{4}B and R_{3}Co_{11}B_{4} compounds have been studied. An analysis is given of the room temperature anisotropy constants of these compounds by using a model of Streever. The values of the rare earth-transition metal exchange coupling J_{RCo}/k_{B} derived by mean field analysis of the Curie temperatures are -11.2 K, -15 K and -20.9 K, respectively. In general, a decrease in J_{RCo}/k_{B} with increasing Co concentration is observed.