Full length sequence of lactate dehydrogenase gene was amplified by PCR from the genomic DNA of Plasmodium vivax Hainan isolate, and named as PvLDH/HN (GenBank No. FJ527750). Sequence analysis showed that the gene had 951 bp, coding 316 aa. Compared with PvLDH/Salvador and PvLDH/Belem, the nucleotide sequence homology of PvLDH/HN was both 99.89%, while the homology of amino acid sequence was 100%. Topology analysis showed that the protein had two transmembrane alpha-helices, which suggested that the protein might be a membrane protein. The major antigen epitope regions (82-95aa) was presented on the protein surface, and formed the specific substrate binding loop, which revealed that it might be an ideal target site for drug action and immunodiagnosis.