A novel method for rapid preparation of Bi2Te3 nano-sized powders with an average particle size of about 70 nm was developed.A starting powder mixture consisting of Bi2Te3 coarse particles of ～5 mm was ground using cryogenic grinding in the liquid nitrogen.For comparison,the conventional high-energy ball milling was used to prepare the Bi2Te3 nano-sized powders.Sintering properties of as-prepared powders was investigated by spark plasma sintering (SPS).The effects of the preparation procedure on the crystallinity,morphology and structure were examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM).It was found that Bi2Te3 was not transformed into a non-equilibrium amorphous phase or decomposed during the cryogenic grinding process,and as-prepared nano-powders possessed excellent sinterability.This technique might also be applicable to other thermoelectric materials.