Abstract: To investigate the relationships of biochar and straw with nutrient and organic carbon pool in tobacco planting soil, field experiments were carried out to study the effects of separately applied biochar, decomposed straw and biochar combined with decomposed straw with the same carbon content on nutrient and organic carbon pool in soils of different tillage layers. The results showed that the fertility (except alkali-hydrolyzed nitrogen) and carbon pool index of soil treated with additional organic materials significantly increased in each tillage layer compared with the treatment of applying chemical fertilizer. The organic matter content in 0-30 cm plow layers of soil treated with biochar was higher than that treated with the decomposed straw. However, the dissolved organic carbon and microbial biomass carbon contents in different plow layers of the soil treated with the decomposed straw were higher than those treated with biochar. Comparing with applying decomposed straw alone, the contents of available phosphorus, available potassium, organic matter and total organic carbon in 10-20 plow layer of soil treated with biochar combined with decomposed straw increased by 22.26%, 6.08%, 8.68% and 9.20% respectively, and the differences were all statistically significant. In conclusion, application of biochar or decomposed straw has a repairing effect on tobacco-planting soil, and the effect of combined application of biochar and decomposed straw is better than the single treatment.