Carbon sequestration is one of the most important ecological services of wetland ecosystem and plays an important role in global carbon budget. This study chooses typical wetlands as research objects and mainly analyzed the carbon sequestration function values of Heihe Wetland National Nature Reserve in Zhangye, which is located in the inland arid region of northwest China and also a typical inland river wetland as well as a water ecological system. Based on the field investigation and experiment analysis, a lot of data are given out to calculate the vegetation carbon storage and solid carbon storage of this area. In addition, it applies the carbon tax method to evaluate the carbon sequestration value. The results showed that the total carbon storage was 596.41 Gg and the carbon sequestration value of the research area was 741 million yuan. Although the carbon sequestration value was far below that of the Sanjiang Plain, The tremendous monetary value could be useful data reference for the development and utilization of land resources, especially in the arid region; it also was significant for the maintenance of carbon sequestration function in wetland ecosystem. At the same time, it would provide the certain reference of carbon sequestration value for China in dealing with global climate change.