Objective:To clone the protein phosphatase (PP) 2A gene in Dendrobium officinale, and analyze the bioinformatics and expression characteristics. MethodsThe RACE technology was used to clone the gene. A series of bioinformatics tools were used to analyze the physiochemical properties of nucleic acids and proteins, conserved domains and subcellular localization. The DNAStar 7.0 and MEGA 6.0 software were used for protein sequence comparison and phylogenetic analysis respectively. The quantitative PCR was used for the analysis of gene expression pattern.  Results:The homology of DoPP2A (GenBank accession KT957552)cDNA, 1 410 bp in length, was 89%～94% with PP2A from other plants. The ORF encoded a peptide chain composed of 306 amino acid with a molecular weight of 35.19 kD and an isoelectric point of 4.79. The deduced protein contained the metallo-dependent phosphatase conserved domains. The DoPP2A did not contain signal peptides or trans-membrane domain, and located in the cytosol. The DoPP2A was highly conservative compared with PP2As from other plants, and was clustered into group A of the PP2A evolutionary tree. The gene transcripts in the roots and stems were 4.41 and 1.45 times respectively than that in the leaves.  Conclusion:The molecular clone and characterization of DoPP2A can provide basis for the research on molecular function during the growth and development of Dendrobium officinale.