Abstract: The somatic embryogenesis of Fraxinus mandshurica Rupr. is often accompanied by browning, and most somatic embryos grow on browning explants.We analyzed the relationship between explant browning and somatic embryogenesis, by adding PVP(polyvinylpyrrolidone), L-Glu(L-glutamic acid) and AgNO₃(silver nitrate) to the culture medium, and studied its effects on browning, somatic embryogenesis and physiological and biochemical characteristics of explants.The results showed that: (1)Low concentration(0.1 and 0.5 g·L^-1) PVP, and 100 mg·L^-1 L-Glu treatment exacerbated browning of explants, but significantly promoted somatic embryogenesis, somatic embryogenesis rate exceeded 60%(increased by 6.59%, 24.08% and 22.88% compared to the control,respectively). (2)The 200 mg·L^-1 L-Glu treatment effectively reduced the browning of explants, the browning rate was 68.11%(down 5.83% compared with the control), but the somatic embryogenesis rate was reduced to 46.32%(down 22.8%compared with the control). (3)The activities of polyphenol oxidase(PPO) and superoxide dismutase(SOD) in explants were lower than those of control after treatment with three anti-browning agents, peroxidase(POD) activity and malondialdehyde(MDA) content were higher than the control.Therefore, it is believed that a low concentration of anti-browning agent can promote somatic embryogenesis, and in this process, an increase in POD activity and an increase in MDA content are involved. We analyzed the biological mechanism of somatic embryogenesis with explants browning and got the frequency of somatic embryogenesis of F.mandshurica.