The composite oxide CuO/Mn3O4 and its mesoporous composite were prepared through co-precipitation method. The preparation conditions of CuO/Mn3O4 were tested and ascertained as following: Mn:Cu, 2: 1; NaOH solution, 25% (w/w); volume, 6 mL; without aging; drying temperature, 90 degrees C; calcination temperature, 200 degrees C; calcination time, 3 h. CuO/Mn3O4, the mesoporous solid, and the mesoporous composite were characterized by X-ray power diffraction (XRD), high-resolution transmission electron microscope (HRTEM). The HRTEM image showed that CuO/Mn3O4 had been loaded into the pores of the mesoporous solid and the average diameter of CuO/Mn3O4 particles was about 4 nm. The specific surface area and the aperture distribution of the mesoporous solid and the mesoporous composite were measured by N-2 adsorption. The catalytic activity and stability of CuO/Mn3O4 and the mesoporous composite were evaluated on a small fixed reaction bed and an online GC. The tar and some other harmful components in cigarette smoke can be reduced by using dual-filters containing the mesoporous composite. Comparing with the reference cigarette smoke, the tar, CO, benzo[alpha] pyrene and tobacco-specific N-nitrosoamines (TSNAs) in the tested cigarette smoke were reduced by 27.2, 23.8, 30. 1, and 38.1%, respectively. (c) 2005 Elsevier B.V. All rights reserved.