The energy deposition, production of displacement and replacement collisions induced by fusion α-particles with energies from 10keV to 50keV are studied by computer code MARLOWE based upon binary-collision approximation. The results are compared with the Monte-Carlo simulation. The number of vacancies is found to be proportional to the elastic energy, deposition, in agreement with analytical theory. The similar profiles are observed for both elastic energy deposition and vacancies. The radiation damages caused by α-particles in different target elements are discussed as well.