Ordered mesoporous carbon (OMC) was used as support for CuOx and MnOx, and the effects of preparation method on selective catalytic reduction (SCR) of NO with NH3 were investigated. The Cu–Mn/OMC prepared by solvent evaporation-induced self-assembly method, named as self-assembly synthesis (S), exhibited higher NO conversion and N2 selectivity than the catalyst prepared by ultrasound-assisted impregnation (I) or mechanical mixing (M). The structural and surface properties of catalysts were characterized by various techniques. XRD and TEM results showed good dispersion of active phases on Cu–Mn/OMC(S). XPS analysis suggested that the surface of Cu–Mn/OMC(S) had the maximum amount of O–C=O groups and chemisorbed O. The strongest acidity and largest amount of oxidative species were further illustrated by NH3-TPD and H2-TPR profiles, which were consistent with the XPS results. Accordingly, these favorable properties may be the main reasons for the outstanding performance of Cu–Mn/OMC(S) in NH3-SCR reaction. Thus, self-assembly synthesis can be considered an effective method for the preparation of OMC–supported catalysts.