Polycrystalline samples of BaV13O18 and SrV13O18 were prepared by solid-state reaction of BaCO3, SrCO3, V2O5 and V at 1773-2073 K in flowing Ar. The crystal structures of BaV13O18 (R-3, a(h) = 12.6293(10) Angstrom, c(h) = 7.0121(4) Angstrom) and SrV13O18 (a(h) = 12.5491(7) Angstrom, c(h) = 6.9878(3) Angstrom) were refined by the Rietveld method using X-ray diffraction data. BaV13O18 exhibited semiconducting behavior with electrical resistivity from 5.8 x 10(-3) to 2.7 x 10(-3) Omega cm at 100-300 K. Electrical resistivity of SrV13O18 ranged from 1.5 x 10(-3) to 1.8 X 10(-3) Omega cm, and it increased slightly up to around 250 K and decreased above 250 K with increasing temperature. Negative Seebeck coefficients of both compounds at 100-300 K indicated that electron was the dominant carrier. BaV13O18 and SrV13O18 showed paramagnetism with the effective magnetic moment of 0.11mu(B) and 0.15mu(B), respectively, at 10-100 K. (C) 2002 Elsevier Science Ltd. All rights reserved.