After developing a procedure for somatic embryogenesis in Fritillaria ussuriensis, dynamics on the syntheses of DNA, RNA, and protein during globular, heart-shaped, torpedo-shaped, cotyledonary, and mature somatic embryo stages was demonstrated by both autoradiography and scintillation counting. The rates of syntheses of DNA, RNA, and protein gradually increase between the globular and cotyledonary somatic embryos stages. DNA, RNA, and protein synthesis rates are in peak at the cotyledonary later stage, precotyledonary stage, and cotyledonary stage, respectively. It appears that more DNA, RNA, and protein are synthesized in the cotyledonary somatic embryo stage than in other stages. All these results indicate that an increased syntheses of DNA, RNA, and protein is associated with the differentiation of embryogenic cells and organogenesis in somatic embryos.