Abstract: After irradiation, some mutation will be occurred between the offsprings of soybean. This test is intended to resolve the law of the traits of the offsprings of soybean after irradiation and it can provide us the theoretical support of radiation breeding. 20 mutate lines derived from Kefeng 14 were analyzed by the main agronomic and quality traits to observe their variability. The results showed that the variation of agronomic traits is more than quality traits of all mutation lines. The days of maturity delay 7 days or more for 65% mutation lines. More than 80% mutation lines have significant variation in plant height, node number of main stem, main stem diameter, pods number of per plant, seed number of per pod, 100-seed weight and yield of per plant. The most mutation lines get a increased on yield of per plant. The yield of per plant is stimulative by the increase of days of maturity, plant height, node number of main stem, main stem diameter, pods number of per plant and 100-seed weight and is limiting by the decrease of seed number of per pod and 100-seed weight. The content of protein, fat and isoflavone has a significant variation for 20%, 30% and 15% mutation lines,respectively. The content of protein and fat is showing a downward trend and upward trend, respectively, which is affected by yield factors to most mutation lines. And the variation of the content of isoflavone has no obvious relationship among each traits.