Translucent single- phase Li-alpha-sialon ceramics were successfully prepared by spark plasma sintering (SPS) at 1750 degrees C for 5 min with a heating rate of 100 degrees C/min. The results show that the volatilization of Li(2)O is prominently retarded by SPS due to the rapid consolidation process. The formation and densification of Li-alpha-sialon are efficiently promoted within a few minutes. The resultant sample possesses relatively high infrared transmittance with a maximum value of 57% at 1.4 mu m, which could be attributed to the dense, homogenous, and equiaxed-grain microstructure with little intergranular glassy phase.