The Monte Carlo simulation code ACAT has been applied to investigate the angular distribution and the energy distribution of atoms sputtered from Cu and Nb targets by normally incident Ar+ions. It is found that there are two important effects which affect the angular distributions and the energy distributions of sputtered atoms, i.e.,the anisotropic effectandthe bulk recoil effect.The former effects means that the recoil flux keeps the memory of the incident ion-beam direction because of the incomplete cascade, while the latter one means the contributions of recoils generated at the deeper layer to the angular and the energy distributions of sputtered atoms.The anisotropic effectis important in the low energy region, and it makes the angular distribution under-cosine and the high energy tail of the energy distribution fall off faster than the Thompson distribution.The bulk recoil effectmakes angular distribution be over-cosine and the peak position of the energy distribution be shifted to somewhat higher energies.