Recently, apatite-type lanthanum silicate, La-9.33(SiO4)(6)O-2, and its analogues with cationic doping in the La/Si site have been attracting significant interests due to their high oxide ion conduction. However, the well-known synthesis method is solid-state reaction, which suffers from problems such as the high sintering temperatures for dense pellets and the impurity phases in the final ceramics. In this paper apatite-type lanthanum silicates were prepared by precipitate method combining with an azeotropic-distillation process. The influences of powder calcination temperature on the relative density were investigated and the optimal calcination temperature was proved to be 1100 degrees C. The main phase of the powder calcined at 1100 degrees C was lanthanum silicate La-9.33(SiO4)(6)O-2 with trace impurities La2O3 and La2SiO5. However, dense pellet (96.63%) with pure lanthanum silicate phase was obtained at relatively low temperature (1550 degrees C). Electrical measurements have shown that conductivity behaviors of the sintered pellets were also calcination-temperature dependent. The highest overall conductivity values, sigma(500) (degrees C) = 1.58 x 10(-3) Scm(-1) and sigma(800) (degrees C) = 2.21 x 10(-2) Scm(-1), were obtained for pellet prepared from powder calcined at 1100 degrees C, which was much higher than that synthesized by other methods. The samples presented activation energies of 0.66 +/- 0.01 eV. The results in the present study demonstrate that the precipitate-azeotropic-distillation approach is an alternative method to synthesize lanthanum silicate powders. (C) 2009 Elsevier B.V. All rights reserved.