Rhizobox was used to study the distribution of copper species in maize rhizosphere and transformation kinetics of copper speciation under controlled condition. Copper speciation was characterized using Tessier's procedure. Exchangeable, carbonate bound, Fe-Mn oxide bound, organic bound, and residuals in maize rhizosphere and control (as bulk soil) were extracted sequentially after various growth period from 20 to 100 days. pH, Eh, dissolved organic carbon, and microbial mass were detected at the same time. ...