Alkaline earth metal titanates ATiO₃ (A: Mg, Ca, Sr, Ba) were prepared from two types of layered potassium titanates [K₂Ti₂O₅ and K_0.6Ti_1.85O₄ (hereafter, Lss)] by using alkaline earth metal molten salts [ACl₂ + A(NO₃)₂ (1:1)]. For A = Ca a single phase of perovskite-type compound was prepared at 600°C by using both starting compounds and the reaction temperature was lower than in 400°C that of the solid state reaction with TiO₂ (anatase) and CaCO₃. A single phase of perovskite-type SrTiO₃ was obtained at 600 and 700°C for K₂Ti₂O₅ and Lss, respectively and these temperatures were much lower than that (1200°C) of the solid state reaction with TiO₂ (anatase) and SrCO₃. In the case of perovskite-type BaTiO₃ a single phase of perovskite-type compound was prepared at 700°C by using both starting compounds and also this temperature was much lower than that (above 1300°C) of the solid state reaction with TiO₂ (anatase) and BaCO₃. Although neither K₂Ti₂O₅ nor Lss could produce a single phase of ilmenite-type MgTiO₃, it was prepared by the solid state reaction with TiO₂ (anatase) and magnesium basic carbonate at 900°C. A single phase of ilmenite-type CdTiO₃ was prepared from K₂Ti₂O₅ by using cadmium molten salts [CdCl₂ + Cd(NO₃)₂ (1:1)] at 500°C. By taking account of the fact that ilmenite-type CdTiO₃ transforms to perovskite-type structure, this preparative method using layered potassium titanates with molten salts preferred to crystallize perovskite-type titanates at lower temperature rather than ilmenite-type ones.