Great concerns were focused on wetland carbon cycle due to its large carbon stock. This study reviewed the internal and internatioal wetland carbon cycle researches, including the temporal and spatial patterns of wetland CO_2/CH_4 emissions, the impact factors on wetland CO_2/CH_4 release, wetland carbon source or sink assessment, as well as the impacts of anthropogenic activity on wetland carbon cycles, respectively. Results showed that various potential impact factors on wetland CO_2/CH_4 release were understood. However, further studys on the interaction of these factors were needed. Moreover, researches on underground carbon dynamics and the interaction of carbon and nitrogen should be strengthened. When evaluating the influences of anthropogenic activity on carbon cycle in wetland, vegetation carbon stock, soil carbon stock and soil carbon emission should be integratively considered. Additionally, more carbon cycle researches should be conducted in areas where no data is available, which will help to not only understand the mechanism involved in carbon processes, and carbon sink or source function of various wetland types, but also reduce uncertainty in regional or global carbon budget assessment.