This study was designed to investigate the biochemical pollutant marker for diagnosis of marine pollutions by the changes in lipid components of the flounder (Pleuronichthys cornutus) in the Yellow Sea of Korea. Hemoglobin levels in serum of wild flounders in the yellow Sea were significantly lower $(15~30\%)$ than those of wild flounder in Pohang (control) of the East Sea. Triglyceride (TG) contents in serum of wild flounders in the Yellow Sea were higher $(15~50\%)$ than those of wild flounder in Pohang. Total and low density lipoprotein (LDL)-cholesterol contents in serum of flounders in the Yellow Sea were significantly higher $(20~25\%;and;15~35\%,;respectively)$ than those of wild flounder in Pohang. Atherogenic index (Al) in serum of wild flounders in the Yellow Sea were significantly higher $(10~60\%)$ than these of wild flounder in Pohang but T-Chol/PL ratios showed almost no change in serum of flounders in the Yellow Sea we examined. These results suggest that near-coastal water as well as neritic water of the Yellow Sea might be affected by pollutant input.