Concentrations of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP)were measured from Nov. 1995 to Sep. 1997 in seawater of Jiaozhou Bay, other ecological factors such aswater temperature, salinity, Chl a and zooplankton were also investigated. Distribution of DMS showedremarkable variation spatially and temporally, ranging from 0 .3 to 52. 3 nmol/L. Seasonally, DMS con-centration was high in late spring and low in autumn and winter. There was similar but weaker seasonalvariation of DMSP. Generaly, DMS concentraion inside the bay was higher than that outside the bay; Concentrations of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) were measured from Nov. 1995 to Sep. 1997 in the seawater of Jiaozhou Bay, other ecological factors such as water temperature, salinity, Chl a and zooplankton were also investigated. Distribution of DMS showed reproducibility variation spatially Seasonally, DMS con-centration was high in late spring and low in autumn and winter. There was similar but weaker seasonal variation of DMSP. Generaly, DMS concentraion inside the bay was higher than that outside the bay;