The hypoxanthine phosphoribosyltransferase (HPRT) catalyzes the conversion of hypoxanthine and guanine to the mononucleotide, IMP and GMP, respectively. For construction of recombinant AcNPV carrying human HPRT, a transfer vector p918 constructed by cloning full-length cDNA for human HPRT into pVL1393 and AnNPV genomic DNA were co-transfected into Sf21 cells. The tissue culture fluid containing extracellular virus was plaque assayed and a recombinant virus with occlusion minus phenotype was obtained by three rounds of plaque purification. Southern blot analysis and PRC results confirmed the insertion of the human HPRT cDNA within the recombinant virus(AcHPRT918). SDS-PAGE and Western blot analysis of the Sf21 cell extracts infected with AcHPRT918 indicated that human HPRT was expressed in insect cell. Large quantities of functional HPRT expressed in insect cells would facilitate characterization of the biological properties of this enzyme.