Abstract:High temperature deformation behavior and microstructure evolution of stoichiometry single phase Ni-50Al intermetallics with an initial grain size of 220 mm was investigated. Results show that the alloy exhibits good plastic behavior under initial strain rate from 7.5×10-4 to 1×10-3 s-1 in the temperature range of 1000-1100 ℃. A maximum elongation of 139% was obtained under initial strain rate of 8.75×10-4 s-1 at 1075℃. Optical metallography (OM) shows that the grains were refined during plastic deformation from initial 220 μm to less than 30 μm. Electron back-scattered diffraction（EBSD）and transmission electron microscopy (TEM) observations show that small-angle boundaries formed continuously during deformation, and changed to large-angle boundaries, resulting in finer grains finally. Microstructure analyses reveal that high-temperature plastic deformation could be attributed to continuously dynamic recovery and recrystallization (CDRR), which was caused by the interaction among gliding and climbing of dislocation.