Abstract: In order to study the changes in the combustion states of cigarettes with different circumferences during puff-by-puff smoking, the samples of cigarettes with three circumferences (17, 20, 24 mm) were designed. The puff-by-puff temperature characteristic parameters (volume V₀, maximum temperature T_max, characteristic temperature T_0.5, and volume-average temperature T_m) of the combustion cone were determined under puff-by-puff smoking condition. The results showed that: 1) As the cigarette circumference increased, the combustion cone volume increased, the proportion of high temperature area decreased, and the difference between T_max and T_m became smaller. 2) During puff-by-puff smoking, the volume of the combustion cone of the 17 and 20 mm cigarettes did not change significantly, and that of the 24 mm cigarette reached its maximum in the third puff, but the maximum temperature did not change significantly. 3) During puff-by-puff smoking, the characteristic temperature and volume-average temperature of the 20 and 24 mm cigarettes generally decreased, while those of the 17 mm cigarette showed a distinct upward trend around the fourth puff. 4) The change rates of temperature characteristic parameters of the cigarettes were consistent during the whole smoking process. The results indicated that the main reason for the differences in puff-by-puff temperature characteristic parameters of cigarettes was the difference in the combustion state of cigarettes before puffing.