High temperature deformation behavior of activated sintered W powder compacts was investigated. The compression tests were carried out in the temperature range between 900 and 110 at the strain rate of . The sintered specimens of Ni-doped submicron W powder compacts showed decrease in W grain size with increasing the Ni content. As the result, the flow stress was significantly increased with increasing the Ni content. We obtained Ni-activated sintered W compacts with the relative density of 94 l%and the average grain size of less than 5. A moderate true strain up to 0.60 was obtained without fracture even at 110 with the strain rate of for the activated W compact despite adding the 1.0 wt%Ni to submicron W powder.