Abstract: The trapped particle in earth's radiation belts is an important factor for the abnormity of spacecraft, so it is necessary to study its distribution in earth's radiation belts. The operational environment of the LEO spacecraft is the inner radiation belt, which is the closest trapped charged particle zone from the Earth, mainly composed of protons of above 10 MeV. This paper mainly concerns the proton distribution in the radiation belt where the LEO spacecraft operates and the current status of the radiation belt modeling. The models commonly adopted for computing the proton flux at present are discussed. They are developed in different periods with different characteristics, and the energy ranges as well as the advantages and disadvantages of each of the models are analyzed. The proton fluxes of different orbits are computed by the models and the results are compared. The proton fluxes should be computed through different models, according to different requirements of different orbital altitudes and energy ranges.