Nanocrystalline SnSe semiconductor was synthesized by a novel solvothermal method. SnCl2, Se, and Na reacted at 130 degrees C for 5 h in an autoclave. Ethylenediamine was used as solvent. The product was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the as-prepared SnSe was of high quality. TEM images revealed that the product was comprised of homogeneous and spherical grains and that the average grain size was about 45 nm. The possible mechanism of the SnSe grain growth is proposed.