Abstract: In order to investigate the relationship between leaf tobacco and the moisture content in mainstream cigarette smoke,the statistical analysis of test data of total sugar,reducing sugar,total nitrogen,Cl-,and K+ contents in 98 tobacco leaf samples paralleled with the moisture contents in mainstream smoke was carried out.The samples were of different cultivars,including K326,Honghuadajinyuan(Hongda),Yunyan85 and V2,from different stalk positions and different producing areas in Yunnan Province.The results showed that:1) the difference of moisture contents in mainstream smoke between K326,Hongda and Yunyan85 was insignificant,the average moisture content was 3.7 mg/cig.,while the average moisture content in mainstream smoke of V2 was 2.5 mg/cig.;2) for the same cultivar,the moisture content in mainstream smoke of upper leaves was higher than that of middle leaves,and that of lower leaves was the least;3) for the same cultivar,some differences in moisture contents in mainstream smoke existed between producing areas,which was not as significant as that between stalk positions,particularly between upper,middle leaves and lower leaves;4) the moisture contents in mainstream smoke positively correlated with total nitrogen content,negatively correlated with total sugar,reducing sugar and K+ contents,but not related to Cl-content.