Density functional theory was used to investigate the possible migration mechanism of the BÀ H activation on carboranes. The effects of inducing groups, mediating atoms and ligands were clarified, and the specific reaction process and driving force of transition metal migration in carboranes were explored. The study of thermodynamics, dynamics, wave function analysis and bond order showed that hydrogen atoms and ligands had remarkable effects on metal migration in carboranes. Results indicated that the transition metal complexes can migrate between B/B or C/B mediated by H-atom, which contributes to the regioselective BÀ H activation of carboranes.