Abstract: In order to selectively reduce harmful components in mainstream cigarette smoke, functional cellulose paper filter was prepared by coating cellulose paper with a functional material, OPTI, which contained amino polymers. The effects of the prepared filter on the release of tar and harmful components in mainstream cigarette smoke were investigated under machine-smoking condition, and in vitro toxicology test of cigarette smoke was also conducted. The results showed that:1) The functional filter selectively reduced the release of crotonaldehyde and hydrocyanic acid (HCN) in cigarette smoke. When the coating rate of OPTI was 13.0±0.5 g/m², the release of crotonaldehyde and HCN decreased by 35.8% and 57.2%, respectively; while tar delivery only increased by 0.3%. With the increase of OPTI coating rate on cellulose paper, the release of crotonaldehyde and HCN was further reduced. Furthermore, the harmful component reducing ability of the functional filter was stable after storing for 10 weeks. 2) During in vitro toxicology test, the viability of cells exposed in the smoke of cigarette with a functional filter was promoted slightly comparing with the control, while bacterial mutagenicity and micronucleus frequency did not change significantly. 3) Another functional filter was prepared by coating cellulose paper with recombined functional material of OPTI and PEG6 (polyethylene glycol 600), the mainstream smoke of cigarette with the OPTI/PEG6 filter showed the reduced release of tar, phenol, crotonaldehyde and HCN by 3.1%, 23.7%, 24.6% and 46.3%, respectively. The overall hazard index of the test cigarette was decreased by 0.91. Moreover, the sensory quality of cigarette was not significantly influenced. Therefore, the recombined material of OPTI and PEG6 may be an ideal coating material for selective reduction of these harmful components in mainstream cigarette smoke.