Abstract: Seawater samples were collected from 48 stations, including 9 vertical stations, in the East China Sea during winter in 2010. Concentrations of dissolved monosaccharides (MCHO), polysaccharides (PCHO) and total carbohydrates (TCHO) were measured with TPTZ method and their horizontal and PN vertical distributions were studied. The results showed that mean (range) concentrations of MCHO, PCHO and TCHO in the surface seawater were 3.8 (0.7~14.9), 6.9 (1.1~20.8) and 10.7 (3.0~25.0) μmol C/L, respectively. The horizontal distributions of carbohydrates were influenced by the Yangtze River Diluted Water, the Taiwan Warm Current and the Kuroshio, and generally exhibited a decreasing trend from inshore to offshore sites. No obvious pattern was observed in the vertical distribution of carbohydrates because of the strong vertical-mixing caused by the northeast wind in winter. The high values in the water column were found in the mixed layer (0~100 m). The correlation analysis between the carbohydrates concentrations and the environmental factors at 3 transects outside the Yangtze River Estuary. The results showed that concentrations of TCHO had a significant linear negative correlation with temperature and salinity, respectively, while the MCHO concentrations had a significant positive linear correlation with chlorophyll a (Chl a).