The ternary oxide catalysts of nickel magnesium silicate with a large surface area (498-784 m(2)/g) can be obtained by calcining a mixture of Ni(NO3)(2), Mg(OH)(2) and SiO2. The large surface area of the catalyst is attributed to its layer structure. The selectivity for buta-1,3-diene formation from ethanol on the catalysts was 90% or more and the yield of buta-1,3-diene was 53 mol%.