The energy levels of zinc-blende GaN quantum dots(QDs)are studied within the framework of the effective-mass envelope-function approximation.The dependence of the energy of electron and hole states on the quantum dot(QD)size is presented.The selection rules for optical transitions are given and the oscillator strengths of the dipole-allowed transitions for various QD radii are calculated with the wavefunctions of quantized energy levels.The theoretical absorption spectrum of GaN QDs is in good agreement with the existing experimental result.