The powders of pure cubic phase of Sb3Nb3O13 were obtained using molten salt method at 1,100 degrees C with incubation time of 3 h. The formation of a kind of compound with hydroxyl restrains the volatilization and oxygenation of antimony oxides. The powder of cubic Sb3Nb3O13 shows octahedral shape and its size lies between 1 mu m and 20 mu m. Densified ceramic was obtained using the Sb3Nb3O13 powders. The microstructure of ceramic samples was studied by XRD and SEM analysis. And the dielectric properties as a function of frequency and temperature were measured between 25 degrees C and 550 degrees C and 100 Hz similar to 1 MHz.