Abstract:A pot experiment was conducted to study the changes of soil catalase, sucrose, nitrate reductase, amylase, alkaline phosphtase, the amounts of soil bacteria, fungi, actinomycete, ammonifier, nitrobacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria at different development stages of flue-cured tobacco. The results showed that during tobacco growth, soil catalase, alkaline phsphtase activity and the amounts of soil bacteria and ammonifier in sandy loam descended first, then ascended and descended again. But soil nitrate reductase, ammonifier in loam soil and potassium-dissolving bacteria in sandy loam significantly ascended at the early stages and then declined during tobacco growth, but ascended slightly again at the end. Soil sucrose, fungi, actinomycete, phosphate-dissolving bacteria in loam soil and potassium-dissolving bacteria in sandy loam descended at the early stages then ascended. Except for soil alkaline phosphtase, the variance analysis showed that all the test materials reached the extremely significant level (p≤0.01) at different growing stages. It suggests that soil enzyme activity and the amount of microorganism could be affected obviously by tobacco growth under the interaction system of the tobacco, soil and microorganisms.