The Red River (Vietnam and China) is a good example of a large Asian river basin, strongly impacted by climate change and human activities. Previous studies showed the increasing influences of human activities and climate on hydrology and suspended solids transfer of the Red River. In this study, using the Seneque/Rivershtrahler model, carbon transfer and outgassing from this river under natural and human pressures were calculated for the present and prospective scenarios for the 2050s. The results showed that the model successfully simulated seasonal and temporal variations of carbon concentrations of river. A riverine organic carbon (OC) export of 327 GgCyr-1 for the year 2014 was calculated for the Red River at Son Tay site. Due to the high allochthonous OC inputs from both point and non-point sources, the Red River system is a heterotrophically polluted system. The 2050s scenario results showed that an increase of 24% in OC concentrations for the whole Red River in the future will occur in response to large increases in the urban populations and that this system will remain a strong source of CO2 to the atmosphere in the future.