Abstract: Based on the data from the comprehensive survey in the Yangtze River estuary and its adjacent waters in November 2015, the distribution characteristics of the particulate organic carbon (POC) and dissolved organic carbon (DOC) and their relationship with environmental factors were analyzed. Results suggested that the concentrations of POC in the Yangtze River estuary ranged from 0.65 to 8.25 mg/L, with an average of 1.34 mg/L. POC concentration decreased seaward, with its highest value occurring in the coastal zones, and, vertically, the POC concentration in bottom layer was higher than in the surface. DOC concentration ranged from 0.77 to 2.69 mg/L, with a mean value of 1.49 mg/L. Similar to POC, DOC also showed higher concentrations in coastal zones and lower in outer sea in horizontal distribution, while, DOC concentration was higher in the surface than in the bottom in vertical distribution, which was opposite to POC. POC had a positive relationship with total suspended matter (TSM), which indicated a profound impact by terrestrial inputs on the POC distribution. The significant correlation between organic carbon and salinity indicated that the effect of salinity on organic carbon was enhanced by the conversion of POC to DOC and the dilution of organic carbon by seawater. The strong correlation between DOC and COD indicated that DOC and oxygen-demanding organic carbon had the same source in some degree, part of DOC might originate from the runoff and sewage discharge along the river.