In this thesis range and energy loss of electrons, protons and alpha particles have been calculated in liquid water using the MCNPX code. These calculations have been done in the energy ranges0.001-10 MeV for electrons, 1-100MeV for protons and 4-100MeV for alpha particles,and were compared with some previous works which show good agreements. Then the ranges of the above mentioned particles were calculated in Al, Si using the MCNPX code and also by integrating the stopping power and results were compared with experimental value and their consistency were discussed at various energies.
