Molecular dynamics simulations were performed for 1-100eV particle bombardments of Si(001)-2×1 surface. The two dimensional pair correlation functions were obtained to investigate the arrangement of surface atoms after such bombardments. The results show that 10eV and 100eV bombardments had the some effects on the behaviour of surface atoms. On one hand, 10eV and 100eV bombardments improved the mobility of surface atoms and produced more dimers. On the other hand, they increased the disordering of surface atom's arrangement and made the surface tend to be amorphous.