Abstract: In order to research the influences of morphological and structural variations of cut filler on the smoke delivery during cigarette burning, a new characterizing method was developed from the aspects of micro-structure of cut filler and planar structure of burning cone. The relationship between the variations of morphological structure of cut filler and the CO delivery in mainstream cigarette smoke was investigated. The results indicated that:1) The structural variation occurred at a temperature range of 300-350℃ when the cut tobacco curled and its width and thickness shrank significantly. 2) The length and plane porosity of burning cone were measured from the slice of the burning cone after embedding and setting treatment. 3) When the width of cut tobacco increased from 0.6 to 1.4 mm, the length of burning cone reduced, the plane porosity of burning cone raised, and the CO delivery per unit mass decreased by 17.42%. 4) When the length of cut tobacco decreased from > 4.0 to < 1.6 mm, the length of burning cone reduced, the plane porosity of burning cone raised, and the CO delivery per unit mass decreased by 16.73%.