Abstract: In this experiment the effects of ultra drying treatment on vigour and antioxidase activity of C. intybus seeds was studied. Seeds of C. intybus were ultra dried with silica gel to reduce the moisture content to concentrations of 8.45%, 5.17%, 3.64%, 2.33%, and 1.69%. Seeds were then sealed in aluminium foil bags and stored in a calorstat at 50°C for 10 d. The seed vigor and antioxidase activities were assessed after they were re-moistened. There were no significant changes of seed physiological parameters under ultradrying or non-ultradrying treatments before temperature treatment. Seed germination rate and vigor index of C. intybus seeds were higher than those of the control under conditions of ultra drying after temperature treatment while the electric conductivity and MDA content were lower than those of the control. The activity of dehydrogenase, peroxidase and hydrogen peroxidase were higher than those of the control. For ultra drying of seeds, 2.33% moisture content was better than other moisture contents for storage effectiveness. The Results demonstrated that with an appropriate ultradrying treatment, C. intybus seeds can maintain robust vitality with enhanced storage effectiveness and thus provide a basis for suitable storage of C. intybus Seeds.