Abstract: 【Objective】 To study the effect of seed maturity on seed vigor of barley in the hope of determining the best harvest time of different varieties. 【Method】P13-3 and Ganpi 4 barley seeds with different maturity were selected for constant temperature germination test and conductivity measurement. Before the germination, the physical indexes such as the length, width, thickness, thousand-grain fresh weight, thousand-grain dry weight and moisture content of different maturity seeds were measured. The germination potential, germination rate, germination index, vigor index, seedling length, seed vigor indicators such as seedling root length, seedling fresh weight and seedling dry weight were measured in the process of germination. 【Result】With the increase of maturity, the length of seeds of the two barley varieties increased at first, then widened, and finally thickened. The difference between thousand-grain fresh weight, thousand-grain dry weight, moisture content and conductivity was significant. With the increase of maturity, the moisture content decreased and tended to be stable; The seedling length, root length, seedling fresh weight, germination index and vigor index increased at first and then decreased; Except the dry weight of seedlings, the other vigor indicators reached significant difference. 【Conclusion】Maturity affects the vigor of barley seeds. The dry weight, conductivity, seedling fresh weight, seedling length and root length of thousand-grain dry weight can be used as reference indicators for testing seed vigor. The seeds of P13-3 seed are better at 36-42 d after anthesis, and the seeds of Ganpi 4 have better activity at 30 days after anthesis, and the seedling quality is good, which is suitable for harvesting.