Abstract:In order to select salt-tolerance germplasms of rice (Oryza sativa) germplasms, the physiological indexes related salt tolerance were studied under salt stress. The results showed that the salt tolerance germplasms, such as Pokkali, Fl478 and JX99, had low conductivity, small cell membrane permeability, and high chlorophyll content in leaf, showing weak salt damage. The malondialdehyde content, the degree of cell membrane lipid peroxidation increased under salt stress. The malondialdehyde accumulated in salt-tolerant germplasm less than that in sensitive germplasm, but the malondialdehyde content in three salt-tolerant germplasms also increased under high salt stress, which destroyed the integrity of cell membrane. The critical saturation deficit in sensitive germplasm R29 greatly enhanced, while the relative water content in salt-tolerant germplasms slightly decreased. So, the order of salt tolerance was JX99 > Pokkali > FL478 > IR29 by fuzzy membership function method.