Abstract: The present work investigates the effect of the dielectric constant mismatch on the binding energies of shallow donor in InAs/GaAs strained quantum well. In the framework of the effective-mass approximation, the binding energies are calculated as a function of the well width and the impurity position by using a variational method. The calculated results show that the effect of the dielectric constant mismatch is considerable, which is in agreement with previous work, and that the effect of strain due to lattice constant mismatch is very small and negligible.