Coastal wetland ecosystem, which has many kinds of special ecological functions, is one of the most important carbon pools on the earth. In recent years, the global climate change caused by the emission of greenhouse gases has increasingly been attented. As a significant carbon sink, the coastal wetland regions play an important role in the global carbon cycle. However, the carbon cycling processes in the coastal wetland are very complicated due to the interactions between land and ocean. Recent research demonstrates that the carbon input is the most important among all the complicated processes as the base of the carbon cycle. The Yellow River estuary wetland is a typical coastal wetland in the Northern China. The organic carbon sources were discussed and the strategies about increasing carbon burial capacity of the wetlands ecosystem were raised in this paper. The sources of organic carbon in the Yellow River estuary wetland were deduced by C/N, stable carbon isotopic compositions and biomarkers.The study showed that the organic carbon sources in the Yellow River estuary wetlands were complex with both terrestrial and marine materials. The C/N, stable carbon isotopic compositions of organic matters and biomarkers distributions showed that the terrestrial input of organic matters to the sediments was more than the marine input. The proportion of marine organic matters increased gradually from inland to coastal areas and from shallow beaches to deeper areas with the enhancing impact of tidal. The organic carbon sources had a significantly seasonal change with primary productivities, runoff of the Yellow River and were disturbed intensively by human activities. On the results of organic carbon sources research, many ways can be used to increase the carbon burial capacity of the Yellow River estuary wetlands such as allocating riverine fresh water input reasonably, protecting vegetation around the estuary and accelerating the succession of plant communities covering the wetlands. The conclusions we drew from the Yellow River Estuary wetland can be extended to other coastal wentlands, especially large estuarine wetlands, because the fundamental principles that drive the biogeochemical processes of the coastal wetlands are basically the same despite the different environmental conditions. The current researches on organic carbon sources of coastal wetland should be improved by extending the study areas, exploring stricter distinguish of carbon sources and systematicly analyzing the influencing factors. Since most researches are non-systematic and merely based on the direct observation rather than the exploration of principles and mechanisms, it is hard to get more quantitative results and effective instructions to the increase of the carbon burial capacity of coastal wetland. Future researches should be enhanced in the following parts: 1) Carrying out more comparative studies of wetlands with different environmental conditions; 2) Searching more specific biological indicators and optimizing date analysis models to make finer distinction of carbon sources; 3) Studying the burial efficiencies of organic matters from different sources; 4) Building the assessment system of carbon burial capacity of wetland, developing and integrating the techniques which can increase the carbon burial capacity of coastal wetlands the most.