Abstract: To study the radiation effects of different intensities of 60Co γ- rays on important agronomic characters of soybean and determine the suitable radiation dose, soybean variety‘Huaidou 13’was used as material and radiated by using 200 Gy, 300 Gy and 400 Gy of γ- rays. The results showed that different radiation dosages significantly reduced the field seedling emergence rate and survival rate of M1 generation population. As the dosage increasing, the emergence rate and survival rate decreased. Compared with the control (CK), the variation range of emergence rate and survival rate was 18.07%-44.34% and 0.89%-24.45%, respectively. Meanwhile, radiation delayed the initial flowering stage of soybean from 3 to 5 days and the maximum delay effect showed up when treated with 400 Gy of radiation. By the same token, radiation affected some other important agronomic traits of M1 generation population, such as plant height, main stem number, effective branch number and pod number per plant, which turned out that the stronger of radiation intensity, the greater of difference in phenotype was. M1 generation group was moderate in size, extreme differentiation types had a certain proportion, phenotypic variation was abundant, and probability of obtaining target traits was high when treated with 300 Gy of radiation, which was suitable for the construction of soybean mutant library. The results of the study provide a foundation for constructing various types of soybean mutant libraries and further research on functional genomics.