Wetlands contain a large proportion of the carbon and nitrogen stored in terrestrial soil pool. Climate change significantly affects plant and soil microorganisms and changes carbon and nitrogen cycling process in the wetlands. These variations would be enlarged by the combined effects of climate change and human activities. In this research, the response of aboveground and underground biological processes in the wetlands to climate change and their coupling relationship, and their effects on the cycling of carbon and nitrogen in soil were summarized. Then the combined effects of climate change and human activities on the plants in the wetlands and availability of nutrient in soil were discussed. At last, several issues of the advancing researches were raised, and some suggestions were made for the future related researches.