Abstract: In order to make clear the effect of seed ultra-drying to growth and resistance of the resulting seedlings, Medicago sativa cv. Longdong was used to be differently desiccated with silica gel method, and pot culture with sand and neutral salt stress was conducted after 1 year storage. The result indicated that after moderate ultra-drying, seedling emergence, plant leaflet number (60 days), root volume, root length and soluble sugar content increased 53.33%—66.67%, 14.02%—58.34%, 36.22%—194.22%, 13.75%—18.66% and 31.5%—36.81%, respectively, while MDA content decreased to 18.09%—74.51%, compared with the control; no significant tendency was found between shoot height/chlorophyll content and seed moisture content; mild desiccation treatment accelerated plant biomass, while consistent seed moisture content decrease restricted plant biomass; root activity (4.59% treatment excluded) and nodule number of each treatment were significantly lower than or with no difference compared with the control, indicating that moderate seed ultra-drying and storage accelerated seedling emergence, leaf and root growth for seedlings grown under neutral salt stress, strengthened plant osmosis regulation and decreased adverse stress, but had no promotion in nodule generation or even affected its formation.