Abstract: Stable carbon isotopes serve as tracers, integrators, and indicators for earth science. Moreover, rapid and accurate measurements of these isotopes are increasingly available. Studies of stable carbon isotopes demonstrate great potential to be more widely applied in the fields of ecology, hydrology and geoscience. Despite several previous reviews on the applications of various isotope systems, rapid development of new techniques and continuous expansion of these techniques to new applications in the field necessitate the publication of timely updates to summarize recent advances in applied stable carbon isotope research and technology. This paper summarizes new applications of stable carbon isotopes to investigate soil carbon cycles, plant physiology and ecology, and tree responses to climate change, and reviews recent progress in stable carbon isotope models. We also highlight areas for improving stable carbon isotope research, including consideration of the effects of interaction between environmental factors and plant genotypes on δ¹³C, the response of water use efficiency to multi-factor interactions and the uncertainty of multi-source isotopic models. We anticipate that this updated review of recent applications, existing problems and current prospects of stable carbon isotopes to ecosystem research will be beneficial for future research in this area.