Abstract: This paper deals with the effect of seawater salinity in sand culture medium on the shoot increments of viviparous propagules and some eco-physiological characteristics of Bruguiera sexangula (Lour.) Poir. seedlings. The results showed that: 1) When the salinity is higher than20‰, the shoot increment postponed and survival rate declined. 2) With increase in salinity (5—35‰), the height growth of seedlings decreased and leaf became smaller in size. 3) With increasing salinity from 5‰ to 35‰, the content of chlorophyll in leaves increased, whereas the content of soluble sugar in leaves decreased, but the soluble protein content was not significantly affected under different saline conditions. 4) The Cl content in leaves increased with increase in salinity. 5) As the salinity increased from 5‰ to 35‰, the transpiration intensity and stomatal conductance of leaves declined. The more adaptable range of salinity for B. sexangula seedling to grow was bellow 15‰ salinity.

Key words: Mangrove, Bruguiera sexangula, Increment, Eco-physiology, Salinity