Abstract: After oxidation of river and marine sediments with mild oxidizing reagents under alkaline conditions, the phenolic compounds in the oxidation products were determined gas chromatographicly and compared with that of lignin oxidation products. The appearance and relative distribution of lignin phenols in sediments were attributed to the influence of terrigenous organic materials. The alkaline CuO oxidation was compared with the alkaline nitrobenzene and the gas chromatographic determination of resulted phenols was tested. The results indicated that CuO is preferable to nitrobenzene as the oxidizing reagent at least for sediment samples and the silylation of resulted phenolic derivatives is essential to gas chromatographic determination with nonpolar capillary column. Clear separation and quantitaive determination of silylated derivatives are realized with only SE-30 capillary column. Sediments from Jiulongjiang River-Estuary-Xiamen Bay have been analized by the settled procedure. Lignin has been found in all the sediments taken from this area with similar oxidation products, suggesting an effect of Jiulongjiang River input on whole the area and that the terrigenous organic matter carried by Jiulongjiang river water is the main source of lignin found in this area. The content of lignin in freshwater- end sediments is higher than that in seawater- end sediments, indicating the effect of freshwater-seawater interaction on the distribution of lignin in this area.