Abstract: To investigate the effects of different rod lengths, circumferences and tobacco cutting widths on mainstream cigarette smoke release, cigarettes with five different circumferences, four rod lengths, and three cutting widths of the same tobacco were analyzed under ISO smoking regimes for the conventional smoke indexes. The releases on per unit tar, per unit nicotine, and per unit burnt cut tobacco weight were studied. The results showed that: 1) Under the same tobacco cutting width and rod circumference, the releases of the conventional smoke indexes increased with the increase of rod length. However no obvious difference was observed among the releases of the same smoke index on per unit tar basis. 2) In the circumference range of 23.0-27.0 mm, the releases of total particulate matter (TPM) and tar on per unit nicotine basis decreased with the increase of rod length; and the negative correlation became more pronounced with the increase of rod circumference. 3) At the same tobacco cutting width and rod circumference, the releases of TPM, tar, moisture and CO per unit burnt cut tobacco weight decreased with the increase of rod length. 4) Under the same tobacco cutting width, the releases of TPM, tar, moisture, and CO per unit nicotine and per unit burnt cut tobacco weight presented the lowest values at the rod length of 100 mm under 5 circumferences. 5) The release of tar extremely significantly positively correlated with both circumference and rod length, while significantly negatively correlated with tobacco cutting width.