Soil salinity is the major environmental stress and largely causes yield losses of crops worldwide. For the present study the halophyte seedlings of Bruguiera gymnorrhiza were selected. Seedlings were collected from mangrove forest in pichavaram, Tamilnadu, India. Seedling with uniform size were selected during September month and each seedling planted in 320 polytene bags separately .Before, each bags size with 12__ampersandsigntimes;18 cm were filled with sand, humus and red sand in 1:2:1 ratio. Various concentration of Sodium Chloride solution (0,100,200,300,400,500,600 and 700mM) were prepared by using distilled water. Plantation were separated into 8 groups, each group containing 40 number of plants. Each group of plants treated uniformly by different concentration of Sodium Chloride solution. In addition to this, plants were irrigated with distilled water and maintained as control (0). The results of investigation were made to study the effect of different concentrations of sodium chloride on growth of the seedlings of Bruguiera gymnorrhiza. The upper limits for the survival of the seedlings were up to 400 mM NaCl. The results indicated that the NaCl salinity stimulated the seedling growth upto the optimal level of salinity (i.e., 100mM and 400mM) and decreased significantly with increased salinity (500 to 700mM). The inhibition of seed growth was proportional to the concentrations of NaCl increased. The highest numbers of shoot length, root length were recorded at 400 mM NaCl concentration. Beyond 400 mM NaCl, the growth parameters increased drastically.