Total RNA was extracted from venom glands of Agkistrodon acutus. The cDNA encoding Lys-49 phospholipase A2 (PLA2) was amplified by reverse transcriptional polymerase chain reaction (RT-PCR). The cDNA was cloned into the pGEMT-vector and sequenced. The open reading frame (ORF) of Lys-49 PLA2 consists of 414 bp encoding 138 amino acids, which includes a signal peptide of 16 amino acids and a matured peptide of 122 amino acids. It shows 76% identity in amino acids with another reported Lys-49 PLA2. Because residue 49 in mature peptide is Lysine, it probably possesses myotoxicity. These results indicate there are at least two kinds of myotoxin in the venom of A. acutus.