Abstract: Disclosed is a catalyst for the oxidative dimerization of toluene, comprising a composition represented by the general formula:Tl.sub.l M.sub.a M'.sub.b O.sub.cwhereinM represents at least one element selected from the group consisting of beryllium, magnesium, calcium, strontium and barium; M' represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, titanium, zirconium, hafnium, niobium, tantalum, zinc, aluminum, gallium, indium and antimony;a is 0.05 to 15;b is 0.