Abstract: NP is a relatively conservative structure protein also is the main recognition antigen and have good middle cross reactive. To express Canine Influenza Virus (CIV) subtype H3N2 NP protein, the NP gene was amplified by PCR and cloned into vector pMD18-T and then sequence determination. The NP gene was cloned into vector pET-32a (+). The recombinant plasmid pET-NP was transformed into Rosetta II (DE3) and induced with IPTG.