Nd--sialons with the stoichiometric composition of Nd0.333Si10Al¬2ON15 were obtained by hot-press sintering at 1800°C for 1h. The thermal shock behavior of the Nd--sialons was examined by a water-quenching technique. The influence of the thermal shock temperature difference (T) and cycle times on the residual strength was evaluated. Equiaxed -sialon grains formed together with a small amount of intergranular phase M (Nd2Si3-xAl¬xO3+xN4-x) and -sialon phase. The residual strength after a thermal shock tended to decrease gradually with increasing T above 500°C. However, the specimens exhibited an improved residual strength (~94% of the room temperature strength) after a thermal shock of T=1100°C. The residual strength presented a gradual decrease with increasing the thermal shock cycle times at T=1100°C, and was still remained ~55% of the room temperature strength after 11-time cycle. It is contributed to the surface oxidation which may results in the healing of surface cracks and the generation of surface compressive stresses.