Abstract:The soybean (Glycine max Merrill) cv. “Heihe No. 3” which is sensitive to imbibitional chilling injury was used as experimental material. From the point of cell membranes and by means of physiological tests, the relation of hydration-dehydration to membrane repairation during rehydration in seeds was discussed, and a new point of view on the acting mechanisms of hydration-dehydration was approached. The resistance of seed to imbibitional chilling injury was obviouslv enhanced, its apparent efficiency displayed the enhance of seed rigor, reduction of leakage, especially the K+/Na+ ratio; increasing the K+-Na+-ATPase activity,. The facts indicate that the function of cytoplasmic membrane was enhanced and maintained normally. In the meantime, the activities of SOD, catalase and peroxidase were all enhanced, and the production of volatile aldehydes were decreased. It shows that the function of cell antiautoxidation system was greatly improved. Based on a series of physiological and biochemical index mentioned above and the comparison of water-absorbed curves, a postulated model of membrane system induced by hydration-dehydration treatment is given. It is considered that the effects of the two processes, i,e. physical membrane repairation as well as the physiological and biochemical repairation, will be persisted in the redehydrated seeds.