Abstract: Recrystallization behaviors of a P/M nickel-base superalloy with high volume percent of γ' phase have been studied. It is shown that above the dissolution tempreature of γ' phase a mechanism for the nucleation is the grain boundary migration induced by strain, below this tempreature, mechanism is the coarseing of the subgrain. Complete decomposition of the γ' phase can occur with subsequent reprecipitation at the recrystallizing interfaces. The migration activation energy of recrystallizing interfaces of γ' phase was 635kJ/mol.