Space radiation environment in LEO circuits including high-energy protons and electrons and ions and secondary particles, effects on electronic devices in a spacecraft. The use of shield to reduce radiation and using software's to analyze the shield thickness and analysis of radiation-tolerant circuits is essential. In this study, by initial analysis of shield amount needed for satellites in LEO by Fluka, Geant4 software's and MCNP code, it was found out that reducing the dose on a piece of less than 10 Krad to reduce the flux of protons (DDD) , for Orbits below 1000km for almost no additional shielding is required. Shield thickness is usually expressed as aluminum thickness equivalent and only considering the effect of satellites shield (Al 1 ~ 2 gr / cm ²) is sufficient to reduce the dose (self shielding effect). High density shield materials (such as tungsten and tantalum) and low density materials (such as polyethylene) can be considered as an ideal shield. The simulations and calculations in the spherical case, the initial dose regardless of the extra protection was achieved with 75 Krad tried to use a different thickness of the shield, the dose reduced to 7.5 Krad.