Abstract:The distribution of continents and oceans on the surface of the Earth possesses obvious symmetricity: if one side is covered with a continent, then the opposite side is coveredwith ocean. The symmetricaldistribution dependson the Earth structure of sphere and layer. The sketch map is worked out by elevation data of the Mars surface from ‘Google Earth’, which helps to discover the distribution symmetricity of the continents and oceans on the surface of the Mars as compared with Earth. The structure of the Earth is lithosphere, asthenosphere solid mantle sphere, and liquid core sphere, proceeding from outer to inner. Analogously, Mars possesses the same or the similar inner structure as Earth, which is the basic mode.