This paper introduces the basic principles and steps of the Monte Carlo Methods used in the electron transport calculation. The electron transport process is simulated by “condensed history” Monte Carlo method. The electron random walk path length is determined by the energy steps. For a single step, the electron energy loss is the total amount of the nonradiative (collisional) energy loss and radiative (bremsstrahlung) energy loss, the nonradiative energy loss in each step is sampled from Landau formulation, and the radiative energy loss and the production of bremsstrahlung photon is sampled from Bethe-Heitler formulation. The direction of electron at the end of each step is sampled from the Gouddsmit-Saunderson multiple scattering formulation. The Moller cross section is used for the sampling of the electron-electron scattering. Finally the electron transport in the space used aluminum alloy, and plane materials is calculated and the results are presented.