A new compound in the Ca-Bi-V-O system with the composition Ca2Bi6V4O21 has been prepared and characterized by X-ray diffraction (XRD). Its thermal and electrical properties have also been investigated. The DTA results show the presence of a diffused weak endo in the temperature range 470-550 degreesC and a sharp endo at 860 degreesC. The melting temperature of this compound was found to be 890 degreesC. The XRD study shows that it has a monoclinic unit cell with cell parameters: 11.655(2), 15.295(2), 15.565(2) Angstrom and beta = 93.70degrees (1). The electrical conductivities were 3.8 x 10(-4) and 0.7 x 10(-4) Omega(-1) cm(-1) at 550 and 470 degreesC, respectively. A highly conducting modification was found to exist above 550 degreesC. (C) 2002 Elsevier Science B.V. All rights reserved.