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Based on the whole genome of porcine endogenous retrovirus (PERV-A) in GenBank, we analyzed the restriction sites of PERV-A genome with software DNAman,and designed 3 pairs of specific primers and 1 pair of nested primers to amplify the whole genome of PERV-A strain from the peripheral blood lymphocytes of a Guangxi Bama minipig that only carried PERV-A. Then, the 4 resulting overlapping fragments were joined in turn and cloned into the binary vector pBluescript II SK (-) with pMD18-T as the intermediate vector to construct the full-length cDNA clone. Meanwhile, 15 mutations of PERV-A-BM cDNA clone were restored by gene site-directed mutagenesis and chemosynthesis. The modified PERV-A-BM was then registered at GenBank, getting an accession number: HM159246. For easy identification, we induced site mutation during the cDNA clone construction by replacing the base adenine ( A ) with cytosine (C) at the 8408 bps site of PERV-A-BM through site-specific mutagenesis. The single site of restricting enzymes Aat II was also induced into the mutant virus. The enzyme digestion and sequencing results show that the full length of the proviral genome sequence of PERV-A-BM was 8774 bp, with 5' UTR, 3' UTR at both ends and ORF in the middle, containing the encoded gen gag, pol and env. The amino acid sequences of the obtained gag and pol have a high homology with those in other PERV subtypes, while the homology in env genes was low. This research has provided a ready eukaryotic expression plasmid of a full-length cDNA for further rescuing PERV. [ABSTRACT FROM AUTHOR]