Abstract: In order to investigate the effects of cigarette paper, tipping paper, filter wrap and filter rod of different parameters on the size distribution of particles in aerosol in mainstream cigarette smoke, sixteen samples of cigarettes with materials of different parameters were tested under ISO smoking regime. After on-line dilution to approximate 1/1000 in concentration, the diameter, number and mass of the particles in aerosol were directly determined by an electrical low pressure impactor (ELPI) with the measurement range from 7 to 9970 nm. The results showed that:1) In the three kinds of pulp, flax pulp affected the increase of mass and number of particles in aerosol more significantly. 2) Air permeability of cigarette paper negatively correlated to the mass and number of particles in aerosol. 3) The citrate content in cigarette paper offered heavier influence on particle's number than on its mass. 4) The raise of air permeability of filter wrap significantly increased particle's number, while did not affect particle's mass. 5) The mass and number of particles in aerosol increased with the raise of air permeability of tipping paper. 6) Comparing with normal and combined filters, grooved filter significantly reduced the mass and number of particles in aerosol. 7) With the increase of filter's draw resistance, the mass of particles in aerosol decreased, the number of particles increased slightly.