Nanocrystalline Bi2Se3 was synthesized by a novel solvothermal method at low temperature. During the solvothermal process, BiCl3, Se, and NaI were kept in an autoclave at 130 degrees C for 4 h. NaI was used as the reductant. Ethylenediamine was selected as the solvent and played an important role in the formation of nanocrystalline Bi2Se3. The product was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). As-prepared nanocrystalline Bi2Se3 consisted of nearly homogenous and spherical grains; the average size was about 25 nm.