In order to investigate the relationship between the chemical indexes and hygroscopicity of flue-cured tobacco, the absorption equilibrium moisture content (AEMC) and desorption equilibrium moisture content (DEMC), total sugar, reducing sugar, total nitrogen, nicotine, chlorine, potassium and pH of seventy-six domestic and imported flue-cured tobacco samples were tested, and the simple correlation analysis, gray correlation analysis and canonical correlation analysis of the obtained data were carried out. The results indicated that: 1) the AEMC and DEMC of flue-cured tobacco extremely significantly positively correlated with its total sugar, reducing sugar and pH, while extremely significantly negatively correlated with potassium, AEMC extremely significantly negatively correlated and DEMC significantly negatively correlated with total nitrogen; their relationships with nicotine and chlorine were not obvious; 2) the chemical components in the order of correlation with AEMC and DEMC were total sugar > reducing sugar > pH > chlorine > nicotine > total nitrogen > potassium; 3) the chemical components in the order of load capacity to canonical variables were total sugar > pH > reducing sugar > nicotine > chlorine > potassium > total nitrogen. The hygroscopicity of flue-cured tobacco was more closely related with its total sugar, reducing sugar contents and pH, however, nicotine, total nitrogen, chlorine and potassium would reflect or affect hygroscopicity to a certain extent.