The ratio between cut tobacco burned at puffing stage and cut tobacco burned during the whole smoking process of a cigarette was defined as smoking puff ratio (SPR), and a method for determining the SPR of a cigarette was proposed. Cigarettes were smoked by a smoking machine at different puffing intervals, the regression model between the increase of puff number and the reduction of smouldering time was established based on puff number and puffing duration. Then the SPR of cigarettes under given smoking conditions could be calculated with the regression model, smouldering time and puff number. The SPRs of cigarette samples made of different auxiliary materials and cut tobacco were determined, and the results showed that the SPRs of cigarettes made of the same auxiliary materials and different cut tobacco were basically constant. SPR was obviously decreased by the ventilation of the filter, however, it increased rapidly with the decrease of puffing interval. The proposed method for SPR determination is simple and convenient, which requires no additional instrument other than a smoking machine and no extra measurements other than cigarette smoking. The finding that SPR is determined mainly by cigarette auxiliary materials is helpful for the design of cigarettes with low deliveries of harmful components.