The isothermal sintering kinetics of nanocrystalline Dy~1~-~xSr~xCoO~3~-~y (x=0.6) were studied, and the sintering activation energy was calculated. The results show that the main densification mechanism is evaporation-condensation mechanism and grain boundaries control mechanism in during the initial and middle sintering stage respectively. The sintering activation energy of Dy~1~-~xSr~xCoO~3~-~y is 5.255×10^4 J·mol^-^1. It appeared as nanometer size effect. The grain boundaries with fast moving resulted in dismatching between grain boundaries and pores moving velocity and the density of nanocrystalline oxides was low. Finally, it formed network structure nanometer sponge state.

Key words: ISOTHERMALS, SOLID-PHASES SINTERING, COMPLEX, KINETIC STUDY, DENSIFYING, RARE EARTH OXIDE, SCALE EFFECT, NANOMETER MATERIALS