To develop the stable transformants of the silkworm (Bombyx mori) BmN cells that could continuously express the exogenous gene based on a non-transposon vector, an expression cassette containing human granucyto-macrophage colony-stimulating factor (hGM-CSF) gene driven by ie-1 promoter from B. mori nucleopolyhedrovirus was inserted into pIZT-V5-His to form a recombinant vector pIZT-IE-hGM-CSF, followed by transfecting the constructant into BmN cells, the stable ie-hGM-CSF cell lines were obtained after being selected with Zeocin. PCR result using the genomic DNA of the transformed BmN cells as template illustrated a specific fragment of ie-hGM-CSF, and Western blotting analysis using an antibody against hGM-CSF demonstrated a specific band with a molecular weight of 22 kDa in the transformed cells, meanwhile, the expression level of hGM-CSF determined by ELISA was about 2 814.7 pg in 10(6) transformed BmN cells.