Prawn white spot syndrome virus (WSSV) is the major pathogen responsible for the high mortality of cultured prawns. A gene (termed as p6.8) encoding a basic peptide was found by screening the cDNA and DNA libraries of WSSV. The peptide was highly homologous with proteins rich in arginine and lysine. A fusion protein containing the p6.8 and green fluorescent protein (GFP) genes was cloned into pBV220 and expressed in E. coli. Gel mobility shift assay indicated that the peptide encoded by p6.8 had the capability of binding DNA and might be involved in DNA packaging.