Wheat seedlings of 48h after germination were irradiated with various dosage of X-rays. High dosage X-irradiation, 8 Gy and 14 Gy can inhibited the growth,decrease the freshness weight of wheat seedlings. The height and weight of wheat seedlings decreased with the development of X-irradiation of dosage The concentration of protein and activity of some antioxidases include ascorbic acid peroxidase (ASA-POD),glutathione peroxidase (GSH-Px) and glutathione transferase (GSH,-,Ts) were observed on 2nd and 4th day after irradiation The concentration of protein in wheat seedlings decreases with the development of X-irradiation of dosage. The concentration of protein on 4th day was higher than that on 2nd day showed that the damage of wheat seedlings induced by X-irradiation was resumed during the culture process. X-irradiation can increase activity of ASA-POD, GSH-Px and GSH-Ts of wheat seedlings,and the increase rate of 14Gy X-irradiation was higher than that of 8Gy. The activity of ASA-POD and GSH-Px increased during the culture process and the activity of GSH-Ts decreased. That's show that wheat seedlings can increase the activity of antioxidases to resist the damage induced by high dosage X-irradiation. The results of low dosage X-irradiation,2Gy is similar as the control.