During the cold season, both the coastal and central areas showed high nutrient concentrations (average value for the euphotic zone) as a result of the well-mixed structure in the water column (Table 2). The concentrations of nitrate and phosphate during the March cruise reached 6 umol L-1 and 0.6 umol L-1. Respectively, whereas they were less than 1 umol L-1 and 0.1 umol L-1 during August in the central yellow sea. Additionally, the nutrient-rich water observed in March was consistent with the occurrence of the YSWC. Based on the results of the 35 องศา n transect. Relative higher nutrient concentrations were present in the central area rather than the coastal area. Nutrient distribution patterns in April were generally similar to that in March, apart from reduction in phosphate concentration within the euphotic zone during April. There was a significant difference between the phosphate concentrations in the central yellow sea and the coastal area (Table 2).