Abstract: In order to reduce the NO_x in mainstream cigarette smoke,the thermal stability,specific surface area,shape,size,catalytic activity for NO decomposition of nanoparticulate perovskite oxide(LaFe0.85Pd0.05Cu0.103) were tested by thermal gravity(TG),X-ray diffraction(XRD),nitrogen adsorption,and transmission electron microscope(TEM).By adding it into paper-making process reconstituted tobacco,the effects of LaFe_0.85Pd_0.05Cu_0.1O₃ on NO_x and other harmful components in cigarette smoke were investigated.The results indicated that the specific surface area and average diameter of the oxide roasted at 700℃ for 2 hours were 17.24 m₂/g and 50 nm,respectively,which had higher catalytic activity for NO decomposition.Comparing with the contrast,a cigarette contains 1.5% of this oxide in filler,the content of NO_x in its mainstream smoke decreases by 13.0%.