Abstract: The hypocotyls from aseptic seeding of Davidia involucrata were studied via LSD analysis and orthogonal design.We firstly induced and screened the callus and then carried out suspension cultures.On this basis,we established the cell suspension culture system of Davidia involucrata,and determined the changes in biomass and pH.The results showed that the hormone combination of KT and 2,4-D induced callus were more suitable for cell suspension culture,and the best callus induction medium was WPM with KT 1.0 mg/L,2,4-D 0.5 mg/L and Vc 1.0 mg/L.The quantity of the original incubated callus and the concentration of Ca²⁺ were the main factors affecting biomass in the cell suspension culture system.The best quantity of original incubated callus was 25 g/L,and the best concentration of Ca²⁺ was two times the concentration of Ca²⁺ in the standard WPM medium.Under dark conditions,the growth change curve for the biomass suspension culture of Davidia involucrata resembled an"S"and the maximum biomass was available in 21 d.Results also showed a relationship between the change in pH and changes in biomass.