The rhiizosphere is the microhabitat where plant roots are contacted with soils, and aria the region where soils, roots and microbes are closely combined and interacted on each other. The rhizosphere microorganisms may act as a "microbememlbrane" in the exchanges of nutrients between soils The dynamics of rhizosphere bacteria related to nitrogen transformation and their enzyme activities were investigated applying simulating pot culture tests with two kinds of soil and two genmtypes of wheat in order to understand the regularities of growth and decline of hacteria and their enzyme activities as well as the relations between them and nitrogen transformation.