Abstract: To explore the long-term effects of continuous application of biochar on improving tobacco-planting soil and tobacco leaf quality, four treatments were set with no biochar (CK), tobacco stem-derived biochar (T1), wasted tobacco leaf-derived biochar (T2), and maize straw-derived biochar (T3). The effects of these treatments on the pH and CEC values of tobacco-planting soil, appearance quality and internal chemical composition of tobacco leaves were studied through a 3-year field experiment. The results showed that pH value and CEC value of soil were significantly increased by applying biochar, and the promotion effect was T2>T1>T3. The leaf appearance quality of biochar treatments was slightly better than CK. After continuous application of biochar, the quality of tobacco leaf was significantly higher than CK, and T2 was significantly higher than T1 and T3. With the extension of experiment period, total sugar, reducing sugar, total nitrogen content, total nitrogen-nicotine ratio, total sugar-nicotine ratio of tobacco leaves increased, while nicotine, chlorine content and total sugar-nitrogen ratio decreased. On the whole, The T2 treatment was more beneficial in improving pH value, CEC value, chemical composition content and coordination index of tobacco leaves. Application of biochar significantly improved soil physical and chemical properties, the content of intrinsic chemicals and their coordination, but its effects were lagged. Along with the increasing of test time, the continuous application of biochar is more conducive to improve the tobacco-planting soil and the quality of flue-cured tobacco leaves.