Low temperature combustion synthesis (LTCS) combines the advantage of solution-based processing with that of high temperature self-propagation. The process can be ignited at low temperature and is sustained by a strong exothermic reaction. As presently described the LTCS process was applied to directly synthesize La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM1020) ultra-fine powder in nitrate-citric acid solution. The LSGM1020 powder prepared by this method has specific surface area as high as 120 m2/g. The effect of solution initial concentration and pH value on the properties of the final powder was investigated.