Atomized powders of MERL76 superalloy were rolled at room temperature and their recrystallization behaviour in the atomized and rolled powders was examined at various temperatures. Further, the superplastic behavior of IN100 superalloy powder compact, consolidated by hot isostatic pressing was examined at 1050°C and in the range of strain rates from 4×10-5 sec-1 to 8×10-3 sec-1. The recrystallized grain size of rolled powder particle was finer than that of the atomized powders. Fine grained materials of full density were obtained at the HIP conditions of 1100°C, 90 MPa and 1 hr using both atomized and rolled IN100 powders. These HIP'ed materials showed a superplasticity and the maximum elongation of these from the rolled powder compact was 110%. This value was slightly lower than that of the materials made from the fine powder compact. The cold rolling was effective for grain refining of coarse powders, but it should be operated in a protective atmosphere to prevent the occurrence of PPB (Prior Particle Boundary).