In order to investigate the effect of irradiation on the sprout inhibition and the relationship between endogenous hormones and germination of embryo for fresh walnut, the germination rate and changes of endogenous hormones of embryo for ‘Liaohe4’ fresh walnut were studied, which were exposed to 60Coγ-radiation at different dose and stored at the room temperature (20±3)℃ and at the constant temperature (27±1)℃ after being stored at (0±1)℃ for 30d. The results showed, at the two storage conditions, the control sprouts at the 20d and 12d respectively, accompanied by ABA content decreased, by the increase of the content of GA3, IAA, ZR and the ratio of w(GA3)/w(ABA), w(IAA)/w(ABA) and w(ZR)/w(ABA), with the largest decreasing and increasing rate against control group. It is proved that endogenous hormone ABA is an inhibitory substance, and GA3, IAA, ZR are simulative material during the process of germination, the germination of embryo of fresh walnut is completely inhibited with the radiation dose of 0.05kGy.