[Objective] The article studies the growth and Cu absorption of Ricinus communis L. callus under Cu stress. [Method] CuSO4.5H20 solutions with different Cu concentrations were added to callus subculture medium; callus was inoculated and Cu resistance index of callus was worked out. Cu content in callus was deter- mined with the method of Varian AA240FS. [Result] With the Cu concentration at 60 mg/L, the growth of callus was inhibited, its Cu resistance index was only 33.87%. With the Cu concentration at 40 mg/L, callus was faint yellow in color, and grew rapidly with its Cu resistance index at 61.29%. Such high level resistance could remain the same after six week after continuous subculture. In the 4t week of culture, Cu resistance index in treatments with Cu concentrations at 10, 20, 30, 40 mg/L was higher than that in the 3rd week, and the content of Cu in callus of the treatments was 0.33, 0.54, 1.16, 1.40 mg/g respectively. [Conclusion] Cu con- centration at 40 mg/L in culture medium can be the threshold for selecting Cu re- sistance R. communis callus.
