physicochemical parameter were examined along the Xijiang River Inner Estuarine waterway from September 2006 to June 2007. There was a striking seasonal variation on the average δC13. The riverine δC13(DIC) was controlled by decomposed condition of the riverine
potential. In view of the riverine δC13(DIC)decreasing for the decomposition of the terrestrial organic matter in the rainy season in summer and increasing for the briny invaded zone extending in the spring dry season along the waterway from the Makou