Abstract: The bulbs of tuberose were treated with 6~Co．7 ray in dose of 10 Gy，20 Gv，30 Gv，40 Gv and 50 Gv respectively and cuhivated in andomized blocks design after treatment．1he untreated bulbs used as control．Survival rate and the height of plant were examined．The result indicated that it Was obviously that the inhibition of both the survival rate and the height of plant would be enhaneed with inerease of the radiation dose ranged in this experiment．1he young bulbs were more sensitive to the radiation than mature ones．According to the survival rate．the height of plant and the result of regression analysis，15—20 Gy can be considered as proper radiation dose for youn g bulbs an d 25—30 Gy f0r ma ture ones in the stan dard of LDso and GR5o values．

Key words: Tuberose(Polianthes tuberosa L．), ^6OCo-r ray, Radiation dose