Abstract: In order to achieve effective removal of NO, A new kind of catalyst, Cu/sepiolite, was investigated. Sepiolite was modified by hydrochloric acid. The modification conditions optimized by orthogonal experiments were: the concentration of hydrochloric acid 1.2 mol/L, the solid/liquid volume ratio 1:20, the soaking time 20 h, and the soaking temperature 333 K. Cu/sepiolite was active for NO reduction with CO under lean-bum condition. The maximum activity was observed on the Cu (w = 0.05) /sepiolite calcinated at 673 K and the conversion of NO reached up 90% at 593 K The addition of Ce and Sm to Cu catalysts could improve the reaction properties. The effects of oxygen content and the GHSV (gas hourly space velocity) on the catalytic activity were also studied. The samples were characterized by thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), temperature-programmed-reduction of H2 (H2-TPR) and BET. The experiment results show that Cu/sepiolite is effective for selective catalytic reduction of NO.