Abstract: The microstructure and γ' phase distribution of FGH95 P/M superalloy under different hot extrusions and heat treatments were investigated. OM, SEM and TEM were employed to study the microstructure after heat treatment and γ' phase's dark field images after aging treatment. Tensile properties at room temperature (20℃) and high temperature (650℃) were tested. The microstructure of instant fracture appearance at high temperature was also analyzed. The results show that under the same heat treatment the higher HIP temperature is, the larger γ'phase size during aging treatment is. Heat treatment processing can change the distribution of γ' phase, and salt cooling can increase the total number of γ' phase with middle size and markedly improve the high-temperature plasticity.