To reduce the oxidation temperature of diesel soot, the KNO3 and KOH supported nK-Ce0.5Mn0.5O2(n=0.05, 0.20 and 0.50) catalysts were prepared by citric acid sol-gel method. Thermogravimetric (TG) and temperature programmed oxidation (TPO) were used to investigate the effects of catalysts on the catalytic oxidation activity and stability of diesel soot. X-ray diffractometer (XRD) was used to characterize the catalyst before and after the TPO experiment. The results show that the K-supported catalyst can reduce the ignition temperature of diesel soot. The 0.50 KOH-Ce0.5Mn0.5O2 has the best oxidation activity for soot under NO atmosphere among all catalysts. After TPO experiments for 10 times, the 0.20 KNO3-Ce0.5Mn0.5O2 catalyst still maintains high catalytic activity with good stability. The diffraction peak of KNO3 does not change, while the diffraction peak of KOH is disappeared, which proves the KNO3-supported catalyst has excellent stability. By preparing a catalyst with suitable performance, the temperature required for diesel particulate filter (DPF) regeneration can be effectively reduced with decreased emissions. <摘要译文>