Abstract: A geneexpression cassette with molecular size of the insert, a recombinant plasmid containingthe PK gene of PRV,equal to vector was cloned through partial repair of the terminal endsof insert and vector, thus transforming them from nonadherent to adherent ones. Theconstructed gene expression vector of PRV with the report gene was further identified byendonuclear enzyme analysis and the biological activity of expression vector wasrecognized directly through transfecting cells to detect its transient expression invitro.