In order to obtain the whole genome sequence of Helicoverpa armigera multiple nucleocapsid nucleopolyhedrovirus (HearMNPV), the genomic DNA of HearMNPV was partially digested by Sau3A I, and the plasmid vector pUC19 was fully digested by SalⅠ, and subsequently filled in by the Klenow fragment. After ligation and ansformation, the inserted sequence showing high identity with that of the v-cath gene was acquired and identified. Its open reading frame (ORF) has 1 026 base pairs, encoding 341 amino acids. In comparison of its nucleotide and amino acid sequences with those of other baculovirus, HearMNPV v-cath shows the highest homology with that of Mamestra configurata NPV-B (MacoNPV_B), but the lowest homology with that of Cydia pomonella GV (C_pGV). It is therefore suggested that HearMNPV v-cath had two ways of evolution: one is point mutation and the other is short nucleotide sequences.