Abstract: The binding energies of donor states (1s, 2s, 2px, 3px) in GaAs-Ga0.7Al0.3As quantum wells are investigated with a variational method under hydrostatic pressure. In the calculation, we take into account the electronic effective mass, dielectric constant and conduction band offset between the well and barriers varying with pressure. Results obtained show that the donor binding energy variation with the well width and the position of impurity under pressure is similar to that without pressure. Also the donor binding energy increases linearly with pressure for all of states in direct gap regime.