Abstract: In order to explore the effects of ventilation distribution on the releases of ketones in mainstream cigarette smoke, the releases of ketones in mainstream smoke were determined by GC-MS with two chromatography columns. The results showed that: 1) A total of 56 ketones were identified qualitatively and quantitatively. Among them, the releases of 27 ketones were more than 1 μg/cig, and their releases accounted for more than 91% of the total release of all 56 ketones, which suggested that these 27 ketones were important in mainstream cigarette smoke. 2) Both filter ventilation rate and cigarette paper ventilation rate negatively correlated to the total release of ketones in mainstream cigarette smoke with coefficients of determination (R²) more than 0.98, and the effect of filter ventilation rate was greater than that of cigarette paper ventilation rate. 3) The ventilation rate of cigarette paper negatively correlated to the releases of 56 ketones and their total release. 4) At the same total ventilation rate of cigarette, the total release of ketones increased with the increase of cigarette filter ventilation rate; and the same total release of ketones could be achieved by different combinations of filter ventilation rate and cigarette paper ventilation rate.