Abstract: 【Objective】 To clone the full-length cDNA of Vaccinium dunalianum protein phosphatase PP2A structural subunit gene （VdPP2AA），analyze the structural characteristics and tissue expression patterns of the encoded protein，thereby providing reference for elucidating the regulatory mechanisms of VdPP2AA gene in the growth and development， secondary metabolism and stress resistance of Vaccinium dunalianum， as well as for its genetic improvement. 【Method】 This study used eight tissue samples of Vaccinium dunalianum as the subject of investigation； VdPP2AA gene sequence was screened based on the third-generation transcriptome database of Vaccinium dunalianum and primers were designed. Using total RNA from different tissues of Vaccinium dunalianum as templates，the full-length cDNA of VdPP2AA gene was cloned by PCR. Combined with sequencing and bioinformatics analysis， the physicochemical properties，conserved domains，signal peptide，hydrophobicity，transmembrane domain，secondary structure and tertiary structure of the encoded protein and the codon preference of VdPP2AA gene were systematically analyzed. Phylogenetic tree of 24 species was constructed based on the similarity of PP2AA amino acid sequences， and an analysis of the usage of synonymous codons （RSCU） was performed. Real-time fluorescence quantitative PCR was used to determine the relative expression of VdPP2AA gene in different tissues of Vaccinium dunalianum. 【Result】 The cDNA sequence of VdPP2AA gene was successfully cloned，its open reading frame was 1764 bp in length，encoding 587 amino acids， the molecular weight was 65.679 kD. VdPP2AA protein contained a total of 42 potential phosphorylation sites， comprising 31 serine （Ser） loci， 10 threonine （Thr） loci， and 1 tyrosine （Tyr） loci. VdPP2AA protein lacked transmembrane helix domains and was a non-transmembrane， non-secretory protein； VdPP2AA protein contained a HEAT superfamily domain that spanned almost the entire protein sequence； the secondary structure was predominantly composed of α-helixes； the predicted tertiary structure indicated that VdPP2AA protein consisted of 15 HEAT repeats， each containing 2 antiparallel α-helixes. A total of 26 high-frequency codons with an RSCU > 1.00 were identified in VdPP2AA gene； most of them ended in AU， and codon adaptability index （CAI） was 0.71， indicating that VdPP2AA gene had a high potential for efficient expression. The results of phylogenetic tree analysis indicated that PP2AA was highly conserved across different species， and RSCU cluster analysis further confirmed the evolutionary conservation of PP2AA. Real-time fluorescence quantitative PCR results showed that VdPP2AA gene was expressed in all eight tissues of Vaccinium dunalianum， but there were great difference in expression levels. The relative expression was the highest in young leaves， and was significantly higher than in all other tissues except flowers （P<0.05）. 【Conclusion】 VdPP2AA gene has been cloned and successfully identified. As PP2AA is highly conserved across different species， VdPP2AA gene is likely to be involved in the growth and development， secon-dary metabolism and stress response of Vaccinium dunalianum.