Abstract: Percarbamide is an important chemical product and a new fertilizer. It is widely used in foreign, but just beginning in china. Effects of changes of pH, active Al and growth of maize in 3 acidic soils induced by Percarbamide were studied. The results indicated that：At 25℃, the changes of pH in acidic soils increased quickly, but soil exchangeable Al decreased, with the increasing concentrations of applied Percarbamide. The time-course experiment revealed that the increase of soil pH was short-term, with a subsequently slow drop after reached their maximum, and there was a obviously negative relationship between soil exchangeable Al and soil pH. Plant experiment showed that mayor roots of maize were shorten obviously, and the growth of side roots were inhibited. moreover, the Al toxicity of maize with Percarbamide were more serious than that without Percarbamide, and majority of Al absorbed by maize were largely in roots, minority were in stems and in leaves．