Bismuth silicate (Bi4Si3O12) nanopowders were prepared by the sol-gel method. Tetraethyl orthosilicate (TEOS) and Bi2O3 were used as the starting materials. The precursors were heat-treated at 750°C for 2 h. The size distribution of Bi4Si3O12 nanopowders is 40–100 nm. The thermogravimetry and differential thermal analysis (TG-DTA) curves, the X-ray diffraction (XRD) patterns and the transmission electron microscopy (TEM) microphotograph of Bi4Si3O12 were discussed. Compared with crystal materials, the excitation and emission spectra of Bi4Si3O12 nanopowders indicated a blue shift.