Abstract: Gladiolus hybridus Hort was irradiated with 60Co—γ to understand the change of main quality indices and biological characters. 6 groups gladiolus bulbs were irradiated by 0、25、50、75、100、150GY 60Co—γ respectively. Then plant them and observe the main quality indices and biological characters. The results showed: the gladiolus’ heteromorphosis increased along with the increase of radiation dosage, but low dosage radiation could promote germination, the number of leaves and the height of plant. It was better for the plant growth at 25GY,the irradiation at the does of 75GY gain the most variation, and at 100~150GY the growth indices all goes down obviously. The proper dose of 60Co—γ ray of gladiolus is 75GY.