Abstract: Chinese narcissus bulbs were radiated by 60Coγ-ray with different dosages. The injury effects of morphology and cytology in M1 generation, the dose effects and the relationship among them were studied. The results indicated that 60Co(-ray was an effective mutagenesis for ornamental plant breeding. It induced the chromosomal aberration and nuclear aberration. There were abundant aberrant types. In chromosomal aberration the frequency of chromosomal bridge was the most. In nuclear aberration the frequency of micronucleus was the most. The relationship between different dosages and frequencies of chromosomal aberration and nuclear aberration of root tip cells in M1 generation was fitted in with the model Y=-0.085+1.0385X, Y=-9.6727+2.3697X respectively. The correlation coefficient was 0.9829 and 0.9874 respectively.