Abstract: The main applications of isotope technology in groundwater research were reviewed, including tracing groundwater recharge sources and water rock interaction, identifying groundwater pollution sources and estimating groundwater age and renewability. The application of stable hydrogen and oxygen isotopes to trace the source of groundwater recharge had become an important aspect of groundwater recharge study. It was helpful to understand the origin of groundwater quality and hydrogeochemical process by analyzing and studyingthe variation of ⁸⁷Sr/⁸⁶Sr、²⁶Mg isotopes in groundwater. Isotope technology had unique value in identifying the source of groundwater pollution, for instance the nitrate source in groundwater could be identified by nitrogen and oxygen isotope (¹⁵N and ¹⁸O)of nitrate. The application of radioisotopes such as ³H and ¹⁴C could not only get the groundwater age, but also help to understand the groundwater circulation and renewability, which was an important reference index for sustainable development and utilization of groundwater.