Abstract: in this study,we studied the effects of the aging condition of high temperature and humidity(40℃、100%HR) on four kinds of Elymus sibiricus L. seeds vigor and physiological and biochemical characteristics. The results were as follows: we found that vigor index of Elymus sibiricus L. seeds had a degressive tendency with prolonging of the aging to deal with Elymus sibiricus L. seeds. The conductivity and soluble suger content of Elymus sibiricus L. seeds had been increased after decreased in a short period of time as the aging gradient extension. The MDA increased with the longer aging. The study showed that ,with exacerbation of artificial aging, POD activity had been no rule changes, SOD activity had been increased and then reduced in the later stage, and CAT activity was weaken after aging. These conclusions will play a very important role to the future research of Elymus sibiricus L. germplasm and provide the basis theoretical.