The migration barrier energy of In adatom on the As terminated InAs(001) surface has been studied by using the first-principles calculation. It is found that the migration barrier energy of the In adatom on the As terminated InAs(001) surface is anisotropic. The migration barrier energy of the In adatom on the As terminated InAs(001) surface is higher than that on the 1 ML-InAs/GaAs(001) surface, the wetting layer surface, and lower than that on GaAs(001) surface. (C) 2004 Elsevier B.V. All rights reserved.