Abstract: Three pairs of rice genotypes,each pair having similar general characters but marked differences in salt tolerance ,were compared in terms of seedling responeses to Nacl stress.Based on such growth indices as appearance evaluation of salt damage relative biomass and fresh/dry matter ratios,it was confirmed that the salt-tolerance genotypes indeed outdid their salt-sensitive counterparts It was found from plant tissue analysis that Na+or Cl-content in the shoot of salt-to-lerant genotypes was significantly Lower than those of salt-sensitive genotypes.Correlation analysis showed that the Na+or Cl-ccntent in the shoot was highly correlated to the above growth indces ,indicating that Na+and/or Cl-content in the shoot can be used as a physiological index of salt tolerance in rice seedlings.