Nanosized Cu–Mn composite oxide catalysts were prepared from potassium permanganate, copper nitrate, n-butanol, and cetyltrimethylammonium bromide as a manganese source, copper source, reducing agent, and surfactant, respectively. The Cu[Formula: see text]–Mn sample possessed a small particle size (10–40[Formula: see text]nm) and a relatively high specific surface area ([Formula: see text]); its main components were Cu[Formula: see text]Mn[Formula: see text]O4 and Mn3O4. As a consequence, the Cu[Formula: see text]–Mn catalyst exhibited good catalytic activity in the oxidation of toluene. At a toluene concentration of 1000[Formula: see text]ppm and a space velocity of [Formula: see text], the [Formula: see text] and [Formula: see text] of the Cu[Formula: see text]–Mn catalyst toward toluene were 239[Formula: see text]C and 250[Formula: see text]C, respectively. Furthermore, even after 30[Formula: see text]h of operation at 275[Formula: see text]C, the conversion of toluene was 99% (at the space velocity of [Formula: see text]).