Impacts of human activities (including development of marine aquaculture) and climate change are among the adverse effects that alter the salinity of the environment that may increase metal mobility of sediment and may cause irreversible adverse effects. Therefore, the study investigated the effect of salinity on the release of Cu and Pb in sediments of 3 of 7 sampled sediments in Soai Rap estuary. The results showed that the release of heavy metals correlates with the salinity, especially at salinity of 3035‰. The results also predicted the adversed effects of Cu accumulation in sediments when it will release into the water column on the oyster's reproductive capacity in the studied sites. In constrast, Pb and Zn are predicted to have no effect on the fertilization and development of oyster early life stages. Based on the distribution coefficient Kd, the bond strength of the metals with sediment decreased in the order of Pb >
Cu >
Zn.Key words: sediment, heavy metal Cu and Pb, salinity.