[en] The effect of different doses of gamma radiation 5, 10, 30, 50, and 70 kr on mitotic index root tip cells of safflower carthamus tinctorius was studled the percentages of mitotic indicies were scored . the highest number was 268, 99, for the cotrcl and the fwest was 129, 45%, for 10 kr at interval 2 . the hichest number registerad after 22 hours for 5 kr (244%)and after 24 hours at 10 kr (2,3%), the sansitivity to radietion in root tip cells wich was traced as a delay in mitosis seems to be dose dependent caused by loss of some stages, the percentages of anaphase, telophase were low and stickiness phenomenon of the chromosomes was also noticed