AIM: The current study was designed to construct eukaryotic expression vector containing NK4 gene and transfect it into human pancreatic cancer cell lines.METHODS: The recombinant of pcDNA3/hNK4 was digested by restriction enzyme, the NK4 gene was cloned into a high effective eukaryotic expressing plasmid which contains CMV2 immediate early gene promoter and then transiently introduced into the pancreatic cancer cell line SW1990 by lipofectamine and clonal cell lines that secrete high levels of NK4 protein were isolated.The expression of NK4 was observed by RT-PCR and Western blot, in vitro the vascular endothelial cell proliferation inhibiting activity of NK4 was examined by 3-[4,5-dimethylthiazolzyl]-2,5-diphenyl tetrazolium bromide(MTT) method. RESULTS: A specific expression of NK4 gene mRNA by lipofectamine-mediated transfer exhibited only in SW1990/NK4 cells,Western blot analysis demonstrated that there was positive expression of NK4 protein(50 kD).The NK4 inhibited proliferation of the vascular endothelial cells in vitro. CONCLUSION: The recombinant of pRC/CMV2-hNK4 is a high effective expressing eukaryotic vector.The bio-engineering product of the NK4 is an angiogenesis inhibitor and may play an important role in the gene therapy for tumor.