Diesel soot oxidation with CuO/V2O5/K 2O/CeO2-TiO2 catalyst samples has been studied. Mixtures of the catalyst with diesel soot lower the oxidation temperature from 601 to 427°C. TG/DTA studies of soot oxidation show that K-Cu-V modification improves the low temperature activity in air. Sample B with 12.5 % K 2O has been found to be most active with peak activity at 427 °C. The activity further improved on incorporation of K-Cu-V, due to the mobility of potassium on melting. Chemical interactions between the K2O and titania result in formation of potassium titanate. In addition, the XRD patterns obtained for samples C and D loaded with higher concentrations of potassium show the formation of solid solutions with the oxides of Ce, K and V. Nevertheless, the variation of potassium content has a limited effect on soot ignition temperature. The catalyst with 12.5 wt. % of K2O, 7.5 wt. % of V2O5 and 2 wt.% of CuO exhibits complete combustion at Tmax=427 °C.