Abstract:We investigated the effect of salinity on seedling emergence, seedling growth, ion accumulation and chlorophyll fluorescence parameters of Suaeda salsa L. from an intertidal zone and saline inland. S. salsa produces dimorphic seeds，i.e. brown seeds with soft，a half-transparent outer testa, and black seeds with a hard black outer testa. The seedling emergence of brown seeds was much higher than that of black seeds for both populations from the intertidal zone and from saline inland. Brown seeds emerged more rapidly and seedling emergence was higher in the population from the intertidal zone than in that from saline inland, compared with black seeds. The maximal efficiency of PSⅡ photochemistry (Fv/Fm) and actual PSⅡ efficiency (ΦPSⅡ) in leaves and the biomasses of shoots of S. salsa from the intertidal zone were lower than those of S. salsa from saline inland at a range of NaCl concentrations. The same trend was found for the concentration of both Na+ and Cl- in leaves at a high salinity. These characteristics suggest that different populations of S. salsa are adapted to different natural saline habitats.