The present invention relates to a novel silver aluminum borate composition useful as a catalyst for oxidation and/or ammoxidation reactions. More particularly the invention is directed to silver aluminum borate having the general formula (x) Ag.sub.2 O.(y) Al.sub.2 O.sub.3.(z) B.sub.2 O.sub.3 where x, y and z are numbers representing molar amounts of the oxides such that the mole fraction of Ag.sub.2 O, calculated as x/(x+y+z) is from about 0.35 to about 0.60, the mole fraction of Al.sub.2 O.sub.3, calculated as y/(x+y+z) is from about 0.10 to about 0.40, and the mole fraction of B.sub.2 O.sub.3, calculated as z/(x+y+z) is from about 0.10 to about 0.45. The invention is further directed to a method for preparing the catalyst, and to its use as an oxidation or ammoxidation catalyst.