Calcined dolomite was utilized as a low-cost and efficient catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as malononitrile and ethyl cyanoacetate to afford substituted alpha, beta-unsaturated carbonyl compounds. Calcination temperature was an important variable which changed the surface areas, textural characteristics and basicity of dolomite catalysts. Among them, natural dolomite was converted to CaO-MgO mixed oxide after calcination at 700 degrees C, which served as the best catalyst for this reaction. It could be reused for four times without significant decrease of the reactivity. The reaction proceeded smoothly under the magnetic stirring condition at room temperature in excellent yields within short time due to the high surface area and reasonable basicity concentration of dolomite-700 degrees C catalyst. The attractive features of this procedure were the mild and facile reaction conditions, excellent yields, environmentally friendly reaction profiles and high recyclability, which made it to be an efficient and attractive strategy for the preparation of alpha, beta-unsaturated carbonyl compounds. [GRAPHICS] .