Objective To study the growth differences of Isatis indigotica sown in spring and autmn,reproductive identity and seedy condition of I.indigotica sown in various times,so as to provide the theoretical foundation for scientific standardization of cultivating process.Methods I.indigotica was sampled at a fixed period.At each stage,the growth of seedling and root system was recorded,blooming and seedy condition was recorded in efflorescence.Results The results showed that I.indigotica turned into genesial cycle after thermostage and the change of plant height and crown of I.indigotica were evidence.There was obvious differences between I.indigotica sown in different times.I.indigotica sown in spring grew better than that sown in autumn before efflorescence,but it grew worse than I.indigotica sown in autumn after seeding.Conclusion The weight of thousand seeds,average yield of single plant,and acre yield are different between the two ways for reserving seeds,but the difference of germination rate of seed is indistinctive,it will not influence the yield next year.The seed quality of I.indigotica sown in spring is better than that sown in autumn,but it must pay regard to the plant falling problem.The two ways are both feasible in the south of China while sown in spring is more suitable in the north of China.