Hydrogen absorption and desorption charactersfics for high coereivity NdDyFeCoNbCuB sintered bulk magnets were studied, by differential scanning calorimetry (DSC) measurement and hydrogenation kinetics measurement. The DSC measurements showed that hy-drogenation of Nd-rich phase occurred in the temperature range of 40-185 ℃, hydrogenation of the tetragonal (φ) phase in the temperature range of 185-220 ℃, as well as the disproportionation of the φ phase that occurred in a broad temperature range from around 500 to 800℃. The hydrogenation kinetics measurements indicated that hydrogen absorption of the bulk magnets at 50 ℃ absorbed more hydrogen than at 150 ℃, although this procedure was slower at 50 ℃ than at 150 ℃. This phenomenon was discussed by means of pres-sure-concentration-temperature (p-c-T) diagrams.