Abstract:This paper proposes an approach to evaluating earth gravitational models (EGM) based on Gauss-Listing classic geoid definition. The classic geoid is defined as an equigeopotential surface. Using this characteristic, we select a geoid as reference surface, then calculate the gravity potentials of different EGMs on the surface, and build an index of gravity potential standard deviation to evaluate EGMs. The goal is to evaluate the theoretical compliance ability of different EGMs and the same EGM applied in different areas of the earth. The results show that the geoid precision of EGM96 and OSU91A are respectively ±11.1 cm and ±14.3 cm, which means that the precision of EGM96 is better than former. Further, the geoid precision of EGM2008, and EIGEN-6C4 are respectively ±8.8 cm and ±8.9 cm, which means their precision is similar. This is consistent with existing research conclusions. However, the geoid precisions of EGM2008 and EIGEN-6C4 are respectively ±11.3 cm and ±11.4 cm for a global geoid, which means that the precision of EGM2008 is slightly better than former.