Abstract: In order to study the influences of filter parameters on the mainstream smoke pH and sensory quality of slim cigarettes, 60 slim cigarettes with different tow specifications, different filter rod pressure drops and different filter ventilation rates were prepared, and their mainstream smoke pH and sensory quality were analyzed. The results showed that:1) Tow specification had no significant influence on both mainstream smoke pH and sensory quality. 2) Mainstream smoke pH increased with the increase of pressure drop of filter rod. For the slim cigarettes with the same tow specifications, the mainstream smoke pH increased with the increase of filter ventilation rate; for the slim cigarettes with different tow specifications, the mainstream smoke pH presented a decrease trend with the increase of denier per filament. 3) The score of sensory evaluation decreased with the increase of pressure drop of filter rod. The scores of sensory evaluation of slim cigarettes with tow specifications of 6.7Y/17 000 decreased gradually with the increase of filter ventilation rate, and those of the slim cigarettes with the other four tow specifications in the suitable pressure drop range of filter rod increased first and then decreased with the increase of filter ventilation rate. 4) Correlation analysis indicated that the pressure drop of filter rods significantly positively correlated to the mainstream smoke pH, while significantly negatively correlated to the sensory evaluation score. Filter ventilation rate extremely significantly positively correlated to the mainstream smoke pH. No statistically significant correlation with sensory evaluation score was found. Filter ventilation rate extremely significantly negatively correlated to aroma, while extremely significantly positively correlated to irritation among sensory evaluation indexes.