Through soaking seeds with different concentrations of GA₃ combination of variable temperature stratifications,we analyzed the content of four hormones(GA₃,IAA,ABA,ZR) in seeds of different periods by high performance liquid chromatography and measuring the embryo length and seed germination rate of M.sieboldii,to learn the relationship among the development of embryo,the levels of endogenous hormones and the regulation of seed dormancy and germination,to provide a theoretical basis for further study of seed dormancy mechanism,to provide a theoretical basis for further research on seed dormancy mechanism.we came to certain conclusions as below:(1)Embryo of mature seeds of M.sieboldii developed incompletely and seed dormancy was mainly due to high concentration of ABA and low concentrations of GA₃;(2)GA₃ treatments could stimulate the morphological maturation of seeds by 30 days,and treatment with GA₃ of 1 500 mg·L^-1 saw the best effect;(3)The whole temperature stratification process could be divided into three stages:Stage Ⅰ(0-70 d),this stage was to complete the further differentiate of the seed embryo;Stage Ⅱ(70-120 d) was the fast grow period of embryo;Stage Ⅲ(120-150 d),seed dormancy was broken absolutely and seeds had the ability to sprout.Whether seeds can break dormancy depends on stage Ⅰ and stage Ⅱ;(4)The changes of GA₃/ABA,IAA/ABA and ZR/ABA consist of embryo growth and development during the ripening of the seeds.The relative level of hormones played an important role in seed dormancy regulation.