Al stresses could induce a series of physiological and biochemical changes in plants. In this paper, different response mechanisms of plants against Al stresses were reviewed. These responses, including exudation of organic acids by roots, formation of mucilage on root surfaces, component changes of cell wall, changes of pH and phenolic constituent, were introduced respectively. The component changes of cell wall under Al stresses were described particularly in detail. Finally, some suggestions on further study of Al toxicity were put forward based on the current research.