Organics included in the sediments taken from Daecheong (DCR) and Keum-River Estuary Reservoir (KRER) were analyzed. The analysis methods were loss by ignition (IG), measurement of organic carbons (Org-C), chemical oxygen demand (COD), and elemental analysis of C, H, N. Sediments were sampled with core sampler from the sediment surface to 35 cm. It was found that sediments taken in 1997 were more polluted than those from 1999 from the results of analysis of the surface sediments taken from June, 1997 to October, 1999. Especially, percentages of Org-C, COD, and C% (by elemental analysis) were larger in the fish nurseries existed area till 1997, Henam (HN) in DCR. Therefore, DCR was more polluted than KRER. It was also certificated with elemental analysis of the sediment samples in 1999 according to the depths. The values of IG, COD, and Org-C of the surface sediments taken from the two reservoirs in 1999 were 4.5～11%, 12,000～51,000 mg/kg, and 0.5～2.5%, respectively. And, And, the values of correlation coefficient (R2) from IG : COD, IG : Org-C, and Org-C : COD graphs were calculated as 0.554, 0.637, and 0.901, each other.