A series of catalysts containing 20 wt.% Of Mn, Ce and Zr oxides deposited on Al2O3, SiO2 and TiO2 has been studied in ketonisation of heptanoic acid. The most pronounced effect of alumina support on catalysts activity has been noted. Manganese oxide catalysts have shown the highest activity. The dependence of the concentration of MnO2 active phase on catalyst activity has been determined. A chemical constitution of the side products accompanying 7-tridecanone has been assigned. Stability of MnO2/Al2O3 catalyst activity in ketonisation of heptanoic acid in long-time test has been measured.