Abstract: This study was conducted with pot experiment, trying to analyze the modifying effects of different organic materials on tobacco planting soil and optimize effective cycling utilization of agricultural waste resources.Three different types of organic materials were used in this study including peat, biochar and steam explosion corn straw, to explore their effects on carbon, enzymatic activity of tobacco planting soil and tobacco root activity.The results showed that with the action of organic materials, the contents of soil total organic carbon and active organic carbon in different treatments all increased significantly compared with the control.The total organic carbon content increased by 45.24% 90 d after transplanting, and the active organic carbon content increased by 238.7%.Peat and steam explosion corn straw promoted the rhizosphere soil carbon pool activity and AOC/TOC, while biochar reduced soil carbon pool activity and AOC/TOC.The effects of different materials on enzyme activity and root activity were different.The activities of soil urease and invertase were promoted by steam explosion corn straw, increased by 66.03% and 210.32% compared with the control, respectively.Peat and biochar had no significant effect on soil enzyme activity but delayed root senescence at mature stages.Steam explosion corn straw inhibited root activity of tobacco plant.