Recently, we found 3 variants of hemocyanin subunit with higher molecular weight in shrimp Litopenaeus vannamei (Named as LvHMCV1-3).In this study, a novel L.vannamei hemocyanin variant (Named as LvHMCV4) was further cloned and characterized.Bioinformatic analysis predicted that LvHMCV4 contains one open reading frame of 2137 bp and encodes a polypeptide of 678 amino acids.It shares 84-99% cDNA sequences identity to that of the classical form of L.vannamei hemocyanin (LvHMC, AJ250830.1) and LvHMCV1-3.LvHMCV4 possesses a conserved structure characteristic of the hemocyanin family and can be clustered into one branch along with other arthropod hemocyanins in a phylogenetic tree.