However, little attention has been paid to the riparian forests that are dependent on the groundwater in hyper-arid regions, although the riparian cottonwood (_Populus fremontii_ S. [PERSON]) forest in northern California's Central Valley (310 g C m\({}^{-2}\) year\({}^{-1}\)) [23] and the riparian mesquite woodland along the San Pedro River in southeastern Arizona (233 g C m\({}^{-2}\) year\({}^{-1}\)) [24], USA remain an exception. Riparian forests represent a primary body of natural oases in the lower reaches of inland rivers in China [25]. For example, the Ejin oasis, which is surrounded by a wide desert and located in the lower Heihe River Basin (HRB), exhibits harsh natural conditions with a dry climate, and the ecosystems in this region are highly vulnerable to climate change [26]. In this hyper-arid region, the Ejin oasis on river sides represents some of the richest desert ecosystems, populated with riparian forest, which is internally controlled and interacts with surrounding deserts [27]. Although the area of the riparian forest in Ejin is not large, there are lot of species of biological importance, and their growth and succession reflect the overall health and stability of the Ejin Oasis [28]. Moreover, the desert riparian forest maintains energy and matter cycles in desert regions [7]. The study of CO\({}_{2}\) fluxes and their environmental controls may provide insights into the health and activities of the riparian forest. Survival, growth and development of riparian forests have largely been dependent on the groundwater [6; 8]. The overexploitation of water resources in the middle reaches of HRB since the 1960s led to a decrease in the discharge of water to its lower reaches, that was also likely contributing to a consequent decline in the groundwater and a degradation of ecosystems along the riparian habitats [29]. To restore the deteriorated eco-hydrological environment in the lower HRB region, the ecological water conveyance project (EWCP) was established in the year 2000, and the water resources have thus undergone strict artificial controls. As a result of the implementation of this artificial water management system, groundwater levels appear to have increased, and the vegetation has experienced a favorable change [30]. Groundwater, as the only available water source, has been used to meet the demands for domestic water supply and the ecologic-environmental water consumption. Therefore, it is essential to investigate the dynamics of carbon storage under artificial water management in this important region. Considering the need for examining the characteristics of CO\({}_{2}\) fluxes and their environmental controls in a riparian forest within the hyper-arid region of Northwest China, the continuous measurements in CO\({}_{2}\) fluxes were carried out using the eddy covariance technique. The purpose of this study was to analyze the capacity, variability and the major environmental controlling factors of carbon dioxide fluxes in the desert riparian forest. This study is expected to broaden our understanding of the response processes and the mechanisms in place for the carbon balance of riparian forests in arid regions to face the further climate change and human activities such as artificial water management controls.