Abstract: Wetland carbon pool is one of the important carbon sinks in regional ecosystems, while wetland carbon cycle is an important link in global carbon cycle. However, in the researches of wetland carbon cycle, traditional methods cannot meet our requirements for investigating microscopic mechanisms. Carbon isotopic method, due to its special merit in providing source and process information, has been used as one of the most important tools, helping us probe more detailed mechanisms of wetland carbon cycle. Aiming at the main objects and the basic methods in wetland carbon cycle research, this paper introduced the basic principles of carbon isotopic method and its advantages in carbon cycle research, and summarized the applications of this method in researching wetland biological processes, water body, sediment, and soil, as well as the greenhouse gases emission from wetland. The deficiencies of carbon isotopic research in wetland ecosystem carbon cycle in China and the future directions of this research were also discussed.

Key words: Phyllostachys edulis, soil respiration, soil autotrophic respiration, soil heterotrophic respiration, labile organic C.