Ge exhibits siderophile, lithophile, chalcophile and organophile behavior in different geological environments, and it has been widely used in the study of mineral deposits, environment sciences and so on. Previous testing technology has restricted the development and application of germanium isotopes in Earth science, but limited research on germanium isotopes has indicated great application potential in cosmography, oceanography and so on. In this paper, the authors summarize the chemical preparation and mass spectrometry, and review the isotopic compositions and fractionation mechanism in nature and experiments.