Mn-Co-Ox catalyst was prepared by the co-precipitation method. The most active catalysts were obtained with a molar Co/(Mn+Co) ratio of 0.1. The results showed that over this catalyst, NO oxidation conversion reached 56% at 150°C and 59% at 175°C with a high space velocity of 35000h-1. Their surface properties were evaluated by means of scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The process of Non-thermal plasma-assisted catalytic oxidation of NO under low-temperature was studied. And the NO conversion could reach 71% with the Non-thermal plasma-assisting at 125°C when the input voltage was 30V. The increasing activities at low temperature (50-150°C) were more apparently higher than high temperature by plasma. And the low-temperature catalytic activity of the catalyst was increased with the increase of the input voltage.