Abstract:The biological effects of nitrogen ion implantation in rice(Oryza satiua L)were stud-ied.As the results of nitrogen ion treatment,the surface layer cells of embryo were carvedand crevices of surface layer and changes of inner structure of embryo were observed.Com-pared with the treatment of gamma rays and sodium azide(NaN3), ion implantation causedlower physiological damages in the M1 generation,but higher mutation frequency of headingdate in M2 The mutation frequency of heading date was 1.00%,higher than those of gammarays(0.76%)and sodium azide( 0.53%).The chlorophyll mutation frequency in M2(0.06%)was lower than those of gamma rays(2 25%)and sodium azide(0.93%)treat-ments and the plant height mutation frequency(0. 62%)was nearly the same as that of sodi-um azide treatment(0.63%),and lower than that of gamma rays treatment(0.93%)).Themutagenic efficiency for chlorophyll was 0.18%,which was lower than those of gamma rays(2.72%)and sodium azide(2. 52%)treatments,while that for plant height was 2. 41%,much higher than those of gamma rays(0.81%)and sodium azide(1. 56%)and that forheading date (1. 78%)was higher than that of gamma rays(1.16%),but a little lower thanthat of sodium azide(1.80%)treatment.