Abstract: Mechanism of somatic embryogenesis system in Dioscorea zingiberensis C.H.Wright was discussed by establishing of excellent somatic embryogenesis system with inducing explant at different culture medium, and changes of endogenous phytohormones content during its development. The studies selected two-year fresh and excellent Dioscorea zingiberensis number 41,using its sterile tress which bourgeoned from bud, which inducing culture medium were MS+BA 1.5 mg/L+NAA 0.5 mg/L, Ls+ BA 1.5 mg/L and 1/2MS+ NAA 1.0 mg/L respectively. And the changes of endogenous phytohormones content during its culture were analyzed. The results showed forming of embryonal cell is benefiting from high IAA, Z and GA3. The paper can provide theoretic reference evidence for adjustment of calli and somatic embryogenesis forming in Dioscorea zingiberensis, and offer reference for tissue culture of other plant.