The experiment was conducted to study the effects of rare earth element lanthanum on adventitious buds induction， plantlets growth and secondary metabolites synthesis of Dendrobium officinale by adding 30-150 μmol·L^-1 La（NO₃）₃ to the media. The effects of 70-90 μmol·L^-1 La³⁺ on induction and growth of adventitious buds were the best. The treatment of 130 μmol·L^-1 La³⁺ could significantly increase chlorophyll content of seedlings， and 110 μmol·L^-1 La³⁺ could significantly promote plant growth with 15.22 times of fresh weight， and 12.05∶100 of dry weight-fresh weight ratio， which was 64.39% higher than that of control. A certain concentration of La^{3 +} could significantly improve the content of four components in D.officinale. The polysaccharide content reached the peak value of 98.84 mg·g^-1 under 110 μmol·L^-1 La³⁺ treatment. The contents of flavonoids， phenolic acid and bibenzyl reached maximum value of 4.31， 7.56 and 21.01 mg·g^-1， respectively， when 90 μmol·L^-1 La³⁺ added to media. Both indexes of bibenzyl and flavonoids were highly correlated with other five indexes， while phenolic acid and chlorophyll content were little correlated with other indexes. This study laid the foundation for further exploring the mechanism of rare earth on promoting growth and improving quality of D.officinale， and provided a theoretical basis for scientific and rational utilization of rare earth elements in plant tissue culture.