In this work, we have looked for the correlation between the observed decay of reflection high-energy electron diffraction intensity oscillation and the critical layer thickness in the case of strained InxGa1-xAs/GaAs heterojunctions. The value of deading time constant of oscillation depends on the mismatch and on growth parameters, too. The decay of oscillation was described by two deading time constants which are responsible for the influences of the parameters mentioned above. The critical layer thickness was valued from the deading time constant responsible for the influence of mismatch only. The critical layer thickness determined this way shows good agreement with the theoretical model. (C) 2002 Elsevier Science B.V. All rights reserved.