The stoichiometric ratios of carbon to nitrogen in wetland plants offer valuable insights into the functionality,stability,and responsiveness of wetland ecosystems to environmental shifts. In this study,we investigated the dominant species and analyzed the variations of carbon and nitrogen stoichiometric characteristics of wetland plants in the riparian zones in central Tibet. The study discussed the relationship between plant carbon and nitrogen stoichiometry and geographical factors,clarified the growth strategies and nutrient distribution patterns of wetland plants,and revealed how geographical factors impact local wetland flora. The results showed that: (1) the mean C and N contents of wetland plants were respectively 325.01 mg/g and 20.76 mg/g,with δ¹³C and δ¹⁵N values ranges of -29.15‰—-12.49‰ and -0.61‰-24.22‰,respectively. The carbon content is influenced by local abiotic environmental factors. The high N content is mainly related to the life form of herbaceous plants,which affected by high altitude,low temperature and arid environment. (2) The C and N variables of wetland plants in different species,different life forms and different sampling sites showed significant differences by one-way ANOVA,indicating differences in resource utilization for wetland plants with different life forms. Plant stoichiometric variations are influenced by species and life forms,yet shifts in large-scale environmental conditions can mask differences in carbon and nitrogen stoichiometry among plant functional groups to some extent. The relationship between C and N variables of wetland plants in correlation and regression analysis showed that the stoichiometric characteristics of wetland plants were closely related to their special habitat conditions and their life forms. (3) The correlation and regression between C and N variables,water content and geographical factors indicated that the changes of latitude,longitude and altitude caused the variations of hydrothermal conditions,and then affected the moisture content and stoichiometric characteristics. The variation of δ¹⁵N value in the geographical distribution may be affected by precipitation,but its value varied with the change of geographical gradient due to the different limiting factors in different altitude stages.