Abstract: The effects of different concentrations of NaCl solution (0, 100, 200, 300, 400 and 500 mmol/L) on growth, biomass, relative water content, membrane permeability, photosynthetic pigments, organic osmolyte content and protective enzyme activity of Paspalum vaginatum were assessed to determine the response of growth and physiological parameters to salt stress. The results indicated that plant height, leaf length, leaf width, root dry weight, stem dry weight, leaf dry weight and erect stem diameter of P. vaginatum under NaCl treatment were significantly reduced compared with the control (no salt). Compared with the control, the relative water content of P. vaginatum leaves was decreased significantly, while the membrane permeability, photosynthetic pigment, MDA and soluble sugar content increased. The activities of SOD and POD and leaf proline content all increased at lower salt levels and then declined, peaking at 300 mmol/L NaCl. This study showed that P. vaginatum has self protecting mechanisms providing tolerance to salinity stress; the threshold of salt tolerance was 300 mmol/L NaCl. The improvement of salt-tolerance in P. vaginatum resulted from the modulation of physiological characteristics.