Dry seeds of the early rice （Oryza sativa L. ）cultivar, Guangluai No. 4, were irradiated with,60,Co-γ-rays, and variation in esterase and peroxidase isozymes of rice seedlings of the M,1, plants under pot culture conditions were investigated. The results showed that number of bands in zymograms of the above isozymes displays regular changes with increase of radiation dose. The biological characteristics of the M,1, plant also changed a great deal. Growth prolonged, plant height, panicle length, grains per panicle, and 1000 seed weight reduced, and the number sterile florets raised.