Abstract: Syringa oblata, S. oblata var. alba and S. reticular var. mandshurica were used as test materials to investigate physiological reactions of photosystem Ⅱ in leaves under NaCl stress using the fast fluorescence transients techniques. And a comprehensive appraisal of photosystem Ⅱ functions on the salttolerance was estimated in clove varieties. The results showed that the salt damage phenotypic characteristics and salt tolerance threshold values were basically the same as the trend of changes in chlorophyll fluorescence parameters in leaves of three clove. Along with the increasing of salt concentration, photosystem Ⅱ functions of three clove varieties were decreased, storage capacity PSⅡ electronic receptors were reduced, and electrons from QA to QB were inhibited. The inhibitions leaded to a reduction on electron transport from PS Ⅱ to PS Ⅰ, and the photosynthetic performance index on energy absorption basis(PIABS) was significantly inhibited. φDo and DIo/RC in leaves of three clove varieties showed an increasing trend. That was to say, the excitation energy could be reduced by increasing the ratio of heat dissipation in leaves of three clove varieties under salt stress, and the leaf salttolerance could be improved. However, the exorbitant ratio of heat dissipation also reduced the energy ratio of electron transport (φEo and ETo/RC were decreased). There were significant or highly significant correlations among different chlorophyll fluorescence parameters in leaves of three clove varieties. The subordinative fuzzy function was used to evaluate comprehensively salt tolerance, results showed that the ordination of salttolerance in photosystem Ⅱ functions from high to low was as follow:S. oblata var. alba > S. reticular var. mandshurica > Syringa oblata.