The diffusion mechanisms of Gd adatom on Cu(110) surface are investigated by means of molecular dynamics.The simulation results show that along ［1 1 0］ direct ion the Gd adatom diffuses by hopping,and the frequency of long jumps is very hi gh.While along［0 0 1］direction,the Gd adatom diffuses by exchanging.The freque ncy of hopping is higher than that of exchanging.The frequency of hopping and ex changing can be described by Arrhenius equation.The calculated diffusion barrier of hopping is 0.097eV and that of exchanging is 0.33eV.Moreover the diffusion b arrier of hopping is calculated by energy relaxation method.