Abstract: In order to specify the effects of soil conditioners on soil properties and flue-cured tobacco growth, four soil conditioners, chitosan oligosaccharide (COS), polyacrylamide (PAM), nano-chitin (NCT) and poval (POV) were used to investigate their effects on soil properties, tobacco growth and chemical components in tobacco leaf in Xiangxian and Fangcheng counties. The results showed that the applications of soil conditioners significantly affected soil proprieties and growth of tobacco. Soil water was increased with reducing soil bulk density. Compared to the CK treatment, soil available K contents of COS and PAM treatments were significantly increased by 21.81% and 19.38% at the maturity stage, respectively. The plant height, width, leave numbers, dry matter accumulation (root, stem, leaves) in COS treatment were significantly increased. Nevertheless, the contents of total nitrogen and nicotine in leaves were decreased by 11.69%-14.03% and 12.26%-33.70%, respectively. Moreover, the contents of total sugar and soluble sugar in leaves were increased by 15.40%-22.92%, 11.43%-27.68%, respectively, while yield, production value and superior tobacco rate was also increased by 11.49%-27.99%, 16.44%-37.07%, 5.28%-22.80%, respectively. Compared to the CK treatment, soil available nitrogen contents of COS and PAM and NCT and POV treatments were decreased but soil available K content did not show regular pattern after harvesting stage, respectively. The effects of conditioners in COS and NCT treatments were better than other treatments. This study indicated that the applications of COS and NCT were more effective to improve soil properties, yield and quality of flue-cured tobacco in a continuous cropping tobacco system.