In this experiment, tobacco suspension cell BY2 was used as the material, and 0.05, 0.10, 0.15, 0.20 mmol·L^-1 AlCl₃ was added to the tobacco suspension cells, and the suspension cell solution treatment with equal volume of deionization water was used as a control. And, according to the above experimental results, 0.15 mmol·L^-1 AlCl₃ was selected, 5 mmol·L^-1 DMTU (H₂O₂ inhibitor), 20 μmol·L^-1 CaCl₂, 15 μmol·L^-1 LaCl₃ (Ca²⁺ channel inhibitor) and 50 μmol·L^-1 ATP was used to analyze the effects of extracellular ATP (eATP) on plant cell death and intracellular H₂O₂ and Ca²⁺ induced by aluminum ion (Al³⁺) stress and to reveal plant the possible mechanism of eATP in regulating cell death under Al³⁺ stress, and further extend the perception of eATP function. The results showed that: (1) with the increase of AlCl₃ concentration, the levels of cell death and intracellular H₂O₂ were increased, while the levels of intracellular Ca²⁺and eATP were decreased; (2) Application of DMTU (dimethylthiourea, a scavenger of H₂O₂) and exogenous Ca²⁺ effectively attenuated the AlCl₃induced cell death, while barium trichloride (LaCl₃, the Ca²⁺ channel inhibitor) aggravated the AlCl₃induced cell death, indicating that AlCl3induced cell death is regulated by H₂O₂ and Ca²⁺; (3) The addition of exogenous ATP effectively impeded the increase of intracellular H₂O₂ production and decrease of intracellular Ca²⁺ under AlCl₃ stress, and the cell death induced by AlCl₃ were also alleviated by exogenous ATP. It can be seen that aluminuminduced cell death is regulated by changes in H₂O₂ and Ca²⁺ levels, and extracellular ATP affects the aluminuminduced cell death by regulating H₂O₂ and Ca²⁺ levels.Theses observations indicated that the level of cell death and intracellular H₂O₂ were increased, while the level of intracellular Ca²⁺ and eATP were decreased in a dosedependent manner under Al³⁺ stress. It can be seen that aluminuminduced cell death is regulated by changes in H₂O₂ and Ca²⁺ levels, and extracellular ATP affects the aluminuminduced cell death by regulating H₂O₂ and Ca²⁺ levels. We predicated that Al³⁺ stress may destroy the synergistic relationship between H₂O₂ and Ca²⁺ in cells by inhibiting calcium channel, and the alleviation effect of exogenous ATP on Al³⁺ induced H₂O₂ elevation may be due to its enhanced antioxidant capacity.