Abstract: In order to study the relationship between the puff-by-puff dynamic draw resistance and ventilation of a lit cigarette, a correlation model for the draw resistance and the ventilation of cigarette under the lit state was established on the basis of the linear network model of cigarette in cold state. The linear relationship between the dynamic draw resistance and filter ventilation rate of the cigarette was established. The established. model was verified with cigarettes of three circumferences, and the results showed that: 1) The average relative errors of the dynamic draw resistance, filter ventilation rate and total ventilation rate between the calculated values by the established model and experimental values were 7.4%, 6.3% and 11.1% respectively, which indicated that the model had a good applicability and high accuracy. 2)There was a linear relationship between the filter ventilation rate and the total draw resistance of the cigarettes during puffing while keeping the values of draw resistance at the filter ventilation holes and rear section of the filter unchanged. 3)During puffing, the dynamic filter ventilation rate and the total ventilation rate decreased gradually with the descend range of 4-6 and 12-20 percentage points with each puff. 4) The established dynamic model could predict the variations in the draw resistance and the ventilation of a cigarette in combustion state, which provides a more realistic reference for cigarette design.