Abstract: In order to screen varieties that are resistant to flood, improve cultivation measures and provide theoretical basis for resposing to \ meteorological disasters.This research made waterlogging treatment on the potted ‘Huadamai9’ in seedling stage and explored the growth condition, physiological characteristics and variation of barley in seedling stage after waterlogging treatment.he results showed that the waterlogging resistance ability was stronger in seedling stage and the barley growth period was less effected under waterlogging treatment within 21 days .The barley growth period delayed with the extension of the waterlogging time. Under Seedling waterlogging ,the plant height, stem diameter and chlorophyll SPAD value of barley were effected and as the extension of flooding processing time, the stress was aggravating. 21 days or even longer waterlogging treatment made the plant height, stem diameter and chlorophyll SPAD value decreace significantly.The spike number, spike length, total grains and real grains, weight of 1000-grains, seed and straw yield were significantly impacted under seedling waterlogging, as the extension of flooding time, seeds and straw yield reduced or even crops failure . The agronomic traits significantly reduced under 21 days’ waterlogging treatment or even longer. Seedling waterlogging had serious effect on the straw forage quality of barley .The longer duration of waterlogging, the poorer forage quality, especially significant more than 21 days’ waterlogging treatment. By comprehensive analysis, the limit time that seedling water flooding had no significant effect on the agronomic traits of barley is 14 days.