The Yellow River has changed into a highly dam-controlled system over the recent decades. Based on gauging records of water-sediment discharge and particulate organic carbon (POC) datasets, this paper investigates the dam impacts on spatio-temporal variability of hydrology and POC transport. With a large part of suspended sediment and POC normally preserved within the Xiaolangdi (XLD) reservoir, erosion of riverbed downstream the reservoir has now become a primary source of sediment and POC to coastal ocean (172 Mt/yr for sediment and 0.56 Mt/yr for POC, respectively). Sediment accumulation and POC burial within the XLD reservoir are 246 Mt/yr and 0.60 Mt/yr, respectively, globally accounting for ∼10% and ∼1% of the retentions in reservoirs. Downstream the XLD reservoir, the averaged Δ 14 C values of POC was −451 ± 25‰, corresponding to a 14 C age of 4763 ± 366 yr BP, indicating that the POC in the lower reaches of the Yellow River was ∼2400 yr younger than that in the Loess Plateau region where most of the sediment and POC are sourced. Petrogenic POC fluxes upstream and downstream the XLD dam were 0.12 Mt/yr and 0.06 Mt/yr, respectively, clearly indicative of large-scale trapping of petrogenic POC by the XLD dam. At present, the XLD dam regulation intercepts this petrogenic POC from the Loess Plateau and enhances the downstream input of biospheric POC ( Fm = 0.85) to the coast. In contrast to the sediment and POC delivery of the rivers worldwide that are primarily dominated by tectonic, climatic and geographic settings, human activities, especially the dam regulation in the Yellow River, have significantly altered river hydrologic regime and overwhelmed the sediment and POC delivery within the river-coast continuum, which has profound impacts on carbon cycling in the coastal margin. Schematic diagram for POC and sediment budget within the Yellow River-Coast Continuum from 2002 to 2014 based on observed and reconstrcuted datasets. • The XLD reservoir acts as a sink of POC coupled with periodic rapid sediment accumulation. • Downstream riverbed erosion is a dominant source of POC to the coastal margin. • Dam regulation has substantially transformed the POC delivery during the WSRS.