The MS, LS, B_5, N_6, H, Nitsch, White,1/2 MS as basic media, supplemented with 0.5 mg/L NAA and 0.5 mg/L BA were used to study their effects on callus growth and secondary metabolites production of Eucommia ulmoides . Light, carbon sources and sucrose concentration were studied with B_5 as basic media. The results showed that B_5 medium was best not only for callus growth, but also for the accumulation of flavonoids.1/2 MS was suitable for the accumulation of chlorogenic acid. 12 h/d illumination increase...