We chose distilled water, pearlite and saline-alkali soil as substrate to investigate the effects of growing substrate and saline alkali stress on seed germination and seedling growth of Suaeda salsa. The results indicated that, with increasing level of saline alkali stress, seed germination rate of Suaeda salsa significantly decreased. With the increase of salt content within 0.00%-3.60%, germination percentage fell to 0% from 89% with a linear relationship. This law may be related to saline-alkali stress rather than substrate. What’s more, the average seed germination rate in soil culture experiment was lower than those in water and perlite culture by 8.00% at salt contents below 1.20%.The result of the experiment of salinity in different substrate were consistent at salt contents overtop 1.20%. Substrate is better than salt contents for good seed germination at salt contents below 1.20%, but when restrictive condition overtops 1.20%, salt contents play a badly important role in seed germination. While seedling emergence increased in the beginning to a peak value and then declined afterwards. Salinity=1.00% marked a watershed in this low, seedling emergence increased in the beginning to a peak value (70%) below 1.00%, seedling emergence declined afterwards, until seedling emergence tailed off to 0%. Which indicates that certain optimal level of salinity is necessary for Suaeda salsa to keep a high survival rate. Salinity plays a dominating role for Suaeda salsa during the period from bud to seedling stage and determines the formation of Suaeda salsa community. Higher or lower salinity than the optimal level may result in the replacement of Suaeda salsa by other plant species and the changes to a zonal vegetation community. When soil salinity is at optimal level, nitrogen can effectively promote the growth of Suaeda salsa. An elevated salt supply may hamper the nitrogen uptake by Suaeda salsa Nitrogen demand to maintain optimal growth of Suaeda salsa may vary with salinity condition. Therefore, both of the salinity and nitrogen should be considered when we choose Suaeda salsa as the pioneer species to restore the severely degraded saline soil in the Yellow River Delta.