Abstract: Experiment was conducted to study salt stress (salt conc. 0,1.5,3.0,6.0,9.0g/L) on seed germination and seedling growth of 4 graminaceous pasture cultivars. The results showed that salt-tolerant ability of pennisetum americanium was higher than others, it maintained higher value and relative value of seed germination rate, germination index , vigor index, and shoot height and root length and its relative value was higher than others treated with salt 9.0g/L. Salt stress increased relative membrane permeability of seedlings significantly, and inhibited the use speed and rate of endosperm overall.