Abstract:Dry seeds of rice were implanted with 15~30keV nitrogen ion beam of various doses。The biological effects in M1 and mutation in M2 were studied,The results showed that the ni-trOgen ion could induce the variation On the chrolnosome structure of rice,The chromosomal alberratiou rate of cells tended to be increased with increase of implanted ion dose。However,the aberration rate was lower than that induced with 60Co γ-ravs.Peroxidase isozymogramsin r1ce seedling were changed after ion beam implanting;Frequency of tbe chlorophylI muta-tion implanted by nitrogen ion beam was higher than that induced by γ-rays.Mutation fre-quencies of heading date and plant height were slmilar between ion beam implanting and γ-rays irradiation