The usefulness of metal isotopes in surface carbonate achieves to trace the paleoenvironment and paleoclimate has not been well constrained. Surface carbonate precipitation is sensitive to a number of environmental conditions including light, temperature, salinity, pH and turbidity (Saenger and Erez, 2016). These condition changes could trigger or impact metal isotope fractionation. Therefore, physical and geochemical variations of trace elements and their isotopes in surface carbonates could be eventually used as proxies for reconstructing past environmental variability. Previous studies have shown that parameters such as pH, precipitation rate and Rayleigh fractionation may explain much (or part) of the variability in coral stable isotopes. Determining the controllers of the stable isotopes variation in surface environments will require considerable additional research using abiogenic precipitation experiments, biologic culturing, micro-analytical techniques and geochemical models(Ferrier-Pages et al., 2018; Saenger and Erez, 2016). In this study, Zn isotope compositions from both the inorganic carbonates and its provenance solution of an endogenic travertine-depositing stream in Baishuitai (Yunnan, SW China) was carefully examined. The Zn isotope fractionation between calcite and aqueous solution (δ66/64Zncalcite-solution) shows a large variation ranging between -0.63 and +0.73‰.The possible impacts of temperature, alkalinity, pH of the solution and the carbonate precipitation rate were carefully investigated and the main controllers were identified. This work provides new insight into the use of Zn isotopic signatures in carbonates for reconstructing paleo-environments and tested the possibility of metal isotopes as proxy of paleoclimate. References Ferrier-Pages, C., Sauzeat, L., Balter, V., 2018. Coral bleaching is linked to the capacity of the animal host to supply essential metals to the symbionts. Glob Chang Biol, 24(7): 3145-3157. Saenger, C., Erez, J., 2016. A Non-traditional Stable Isotope Perspective on Coral Calcification. 181-205.