Lithium solid electrolyte 2Li(3)Bi . SLiCl was prepared and was characterized by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The electrical conductivity of the prepared sample was determined from room temperature to 250 degrees C by PAR 368-1 AC-impedance spectrometer. The frequency measurement range was between 4 Hz and 100 kHz. The experimental results showed that the 2Li(3)Bi . 3LiCl lithium solid electrolyte has a high conductivity of about 1 x 10(-4) S/cm at 100 degrees C and 1 x 10(-2) S/cm at 350 degrees C.