[Objective] To study the dynamic changes of composition content and growth of Dendrobium candidum test-tube plantlet in different planting months.[Method] The dynamic changes of Dendrobium candidum test-tube plantlet were analyzed by determining stem height,stem diameter,average fresh weight,contents of polysaccharide and amino acid in different planting months.[Result] With prolonging of cultivation time,stem height and arerage fresh weight increased gradually,stem diameter gradually decreased,the content of polysaccharide rose first and fall later while reaching its peak at December,the contents of main amino acids and total amino acids were in a linear upward trend with varying degrees in different growth stages.[Conclusion] The study has revealed the variation of composition content and growth of tube culture seedling and provided references for rational utilization of Dendrobium candidum tube culture seedling. [Objective] To study the dynamic changes of composition content and growth of Dendrobium candidum test-tube plantlet in different planting months. [Method] The dynamic changes of Dendrobium candidum test-tube plantlet were analyzed by determining stem height, stem diameter, average fresh weight, contents of polysaccharide and amino acid in different planting months. [Result] With prolonging of cultivation time, stem height and arerage fresh weight increased gradually, the content of polysaccharide rose first and fall later while reaching its peak at December, the contents of main amino acids and total amino acids were in a linear upward trend with varying degrees in different growth stages. [Conclusion] The study has revealed the variation of composition content and growth of tube culture seedling and provided for rational utilization of Dendrobium candidum tube culture seedling.