La and Sr have recognized as elements of high level radioactive wastes immobilized by solid solution with CaTiO3. For forming solid solution with CaTiO3, the solution combustion synthesis (SCS) process was applied and the powder characteristics and sinterability were investigated. The proper selection of the type and the composition of fuels are important to get the crystalline of CaTiO3. When glycine or the mixtures of urea+citric acid with stoichiometric composition was used, the solid solutions of Ca(La, Sr)TiO3 were entirely produced. The combustion synthesized powder seemed to have a good sinterability with the linear shrinkage of more than 23% up to 1400oC, while that of the solid state reacted powder was less than 19% at the same conditions.