The high temperature deformation behavior of Al 6061 composites reinforced with SiC and Al2O3 particles has been studied in the temperature range of 300-550degreesC and the strain rate range of 0.1-3.0/sec by hot torsion test. The deformation efficiency eta, given by (2m/m + 1), where m is the strain rate sensitivity, is calculated as a function of temperature and strain rate to obtain iso-efficiency contour map. The composite reinforced with SiC particle exhibited a domain of dynamic recrystallization (DRX) with a peak efficiency of similar to40% at the temperature range of 450-500degreesC and strain rate range of 0.2-0.5/sec. On the other hand, the composite reinforced with Al2O3 particle showed the DRX domain at the temperature range of 450-480degreesC and strain rate range of 0.1-0.2/sec. The characteristics of these domain have been investigated with the help of microstructural observation and hot ductility measurements.