Abstract: To study the factors influencing the combustion cone falling propensity (CCFP) for slim cigarettes, lit slim cigarettes were assessed via an in-house developed CCFP instrument and associated test methods. Four factors (cigarette weight, combustion promoter content in cigarette paper, moisture and stem contents in cut tobacco) on the CCFP of slim cigarettes were investigated through single-factor experiments, and results were analyzed by partial least square method (PLS). The results showed that:1) The CCFP of slim cigarettes sharply increased with the decrease of cigarette weight, greatly increased with the increase of the combustion promoter content in cigarette paper. It also clearly increased with the reduction of the moisture content in cut tobacco and slightly increased with the increase of the stem content in cut tobacco. 2) The linear relationships between the four factors and the CCFP of slim cigarettes were significant. The effect of cigarette weight was the greatest, followed by the combustion promoter content in cigarette paper, the moisture content and the stem content in cut tobacco. 3) By applying the above knowledge, the CCFP of a commercial slim cigarette was significantly reduced via increasing the cigarette weight during manufacturing.