Abstract: Ultra-dry seed storage is a new seed storage method. Ultra-drying is benefit to keep the stability of the structure and function of the membrane system, and is help to keep the integrity of the genetic substances and the ultra-structure of the cells, the activity of the scavenging free radical system is higher , the free radical level is lower, the lipid peroxidation was restrained, so improved the ultra-dried seeds storability . The optimum seed water content is affect by many factors, such as the synthesis and accumulation of protein, fat, carbohydrate and the storage temperature also. The effects of different ultra-dried seeds are different , and the best ultra-drying methods are different also.