Composites with high surface area are excellent supports used in catalysis. Silica-alumina composite (SAC) comprised of silicon and aluminium oxides were synthesized by microwave, co-precipitation and sol-gel methods. Physico-chemical properties of the composites were evaluated to determine surface area, pore volume, pore size, average particle size, total acidity and structural properties. As observed from BET surface analysis, composites have average particle size in the range of 13-19nm, surface area is 324-453 m2/g, pore volume is 0.35-0.70cc/g and total acidity is 0.314–0.392mm/g. All three methods are suitable for the synthesis of new composites of SAC type, however synthesis by microwave route could help in exponential increase in surface area and other properties.