Abstract: In order to clarify the effect of fired soil on the growth of tobacco roots, a pot experiment was carried out to study the effect of different application amounts of fired soil (CK:no fired soil, T1:2% fired soil, T2:4% fired soil, T3:8% fired soil) on the rhizosphere soil pH, soil nutrients, root morphology and the contents of nitrogen (N), phosphorus (P) and potassium(K) in tobacco seedlings. The results showed that, (1) compared with CK, different fired soil treatments significantly increased the contents of available potassium and available phosphorus in rhizosphere soil, and reduced rhizosphere soil pH by 0.37-0.59 units; (2) Compared with CK, T1, T2 and T3 treatments significantly increased plant shoot dry matter by 21.94%, 38.76% and 80.24%, respectively, and the root dry matter increased 67.50%, 92.50% and 87.50%; In addition, different fired soil treatments significantly increased the total root length, root surface area and root volume of plant roots; (3) Compared with CK, the fired soil treatments significantly increased the accumulation of N and P of tobacco shoot by 37.88%-88.05%, 49.95%-55.77% and 34.16%-109.33%, and significantly increased the accumulation of N, P and K of tobacco root, by 71.17%-97.75%, 45.34%-66.91% and 87.27%-128.99%, respectively. In summary, the application of 8% fired soil has a remarkable effect on improving soil nutrient properties, increasing tobacco plant biomass and increasing tobacco plant nutrient accumulation.