By using the recombinant baculovirus expression system, the chimeric antibody against human small cell lung carcinoma was expressed in the cells and larvae of silkworm Bomyx mori N (BmN). The chimeric antibodies produced in BmN cells and larvae which were infected with recombinant viruses rNPVL2, rNPVH17 and dual-recombinant virus rNPVLH19 were detected by Western blot analysis. The co-expression products of heavy- and light-chain genes in silkworm larvae revealed stronger immune binding activity than the single product of heavy or light chain gene expression.