To enhance the production efficiency of foreign protein in baculovirus expression system, the effects of polyhedrin fragments were investigated by fusion expression them with the enhanced green fluorescence protein (EGFP). Recombinant viruses were generated to express EGFP fused with polyhedrin fragments based on the minimal region for self-assembly and the KRKK nuclear localization signal (NLS). The increase of EGFP production by fusion expressions was confirmed through protein and fluorescence intensity analyses. The importance of nuclear localization for enhanced production of EGFP was shown by the mutation of the NLS within the fused polyhedrin fragment. Among the fusion expressed protein in cytoplasm, the most hyper-expression was observed in the fusion of amino acids 32 to 59 of polyhedrin. Polyhedrin fragment fusion expression with classical swine fever virus E2 protein also resulted hyper-enhanced expression of E2 protein. However, the fusion expression of porcine circovirus ORF2 with polyhedrin fragment did not show significant enhance of ORF2 production. These results suggested that the enhancement of foreign protein production when fused with polyhedrin is caused by the enhanced stability of expressed protein.