Abstract: Material density is relative to species of elements and their atomic arrangement. Solid material density lies on crystal structure and chemical bonding properties. It is illustrated that the state of density in the Earth’s interior layers and the result of their distinctness. As the depth increases, temperature and pressure will increase, the composition of metallic bond and covalent bond will increase. The density distinctness of celestial bodies is discussed. The research of the state of temperature and pressure in the Earth’s layers will conducive to the exploiture and improvement of synthetic materials.

Key words: density, crystal structure, chemical bonding properties, density of Earth’s materials, the densities of planet and fixed star