Single-crystal BaH2SiO4 nanowires have been fabricated by a hydrothermal process. The nanowires were characterized using X-ray diffraction (XRD), transmission electron microscope (TEM) and high-resolution transmission electron microscopy (HRTEM). The nanowires are [2 1 0]-oriented growth with diameters 20-30 nm and length reaching up to several micrometers. The formation mechanism of the nanowires was discussed based on structure feature of the material, which can be regarded as a sequence Of SiO4 groups alternating with one type Ba atom (I), these strings of barium atoms and tetrahedron are linked through another type Ba atom (II) located between the tetrahedron. The electrical property was measured using a standard Sawyer-Tower circuit and compared with that observed in corresponding single crystal. (C) 2003 Elsevier Science B.V. All rights reserved.