Based on existing cross-section data and general theories, a Monte-Carlo co
mputer program named NEUTRON for calculating non-ionizing energy loss (NIEL
) and ionizing energy loss (IEL) of neutrons in materials was written. The
amount of IEL & NIEL and their distributions irradiation-induced by 1MeV ne
utrons and protons in common semiconductor material Si were calculated with
NEUTRON and introduced TRIM95, respectively. These results were analyzed a
nd compared with literatures.