Abstract: The distributions of concentrations of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and dissolved free methionine (Met) and their control factors were studied in surface water of the East China Sea (ECS) during October 2012.The concentrations of silicate (SiO₃-Si), dissolved inorganic nitrogen (DIN) and phosphate (PO₄-P) ranged from 0.11 to 1.76, 0.08 to 0.56 and 0.013 to 0.054 mg/L, respectively, with the average values of 0.50±0.36, 0.19±0.11 and 0.024±0.0098 mg/L.Higher concentration of nutrients appeared in the upwelling region of the southwest ECS.The concentrations of DMS, DMSP and Met ranged from 0.47 to 6.46 nmol/L, 9.44 to 54.57 nmol/L and 3.48 to 14.42 nmol/L, respectively, with the average values of 3.10 ± 1.93, 28.05 ± 14.17 and 6.19 ± 2.30 nmol/L.The horizontal distributions of DMS and DMSP have decreased trend from inshore to offshore, with the silimar pattern as chlorophyll a (Chl a).The ratios of DMS/Chl a and DMSP/Chl a in the water column ranged from 2.59 to 27.66 mmol/g and from 27.37 to 103.34 mmol/g, respectively, with average values of 11.46 ± 5.02 and 65.08 ± 23.41 mmol/g, which corresponded well with the dominant phytoplankton of the algae. Furthermore, the sea-to-air fluxes of DMS in autumn were from 0.89 to 105.50 μmol/(m²·d), with an average of (35.65 ± 31.53) μmol/(m²·d).