The annealing effects of InAs layers with different thicknesses in a GaAs matrix were investigated. The diffusion enhancement by strain, which is well estabished in strained quantum wells, occurs in InAs/GaAs quantum dots(QDs). A shift of the QD luminescence peak towards higher energies results from this enhanced diffusion. When a significant portion of the strain in the structures is relaxed by misfit dislocations, the diffusion becomes negligible, and annealing tends to generate additional dislocations. By these why the QD peak energy is weakly affected and the luminescence intensity decreases could be explained.