Abstract: In order to study the influences of cigarettes circumference and filter ventilation rate on the releases of alkaline aroma components in mainstream cigarette smoke, dichloromethane extraction and GC/MS analysis were used to determine the releases of 21 alkaline aroma components in mainstream smoke of cigarettes with different circumferences and different filter ventilation rates. The results showed that:1) The total release of all the alkaline aroma components per gram cut tobacco increased with the increase of cigarette circumference, while the quantity decreased with the raise of filter ventilation rate. 2) The results of variance analysis indicated that there were extremely significant differences in the releases of pyridine, pyrazine and quinoline aroma components and the total release of alkaline aroma components among the cigarettes of different filter ventilation rates, and so did the releases of pyrazine and quinoline aroma components among the cigarettes of different circumferences. 3) When filter ventilation rate increased at a same extent, the decrease extent of the releases of pyrazine aroma components was the largest, followed by those of pyridine and quinoline aroma components.