Objective: To screen preliminarily the DNA fragment with enhancer (enh) activity in human heparanase (HPSE) gene. Methods: Plasmid vector pEGFP-N1 was reformed into pEGFP-MU by adding the rest-riction enzyme cutting site Kpn I and Sal I in its DNA sequence. The DNA sequences in the upstream and downstream of human HPSE gene promotor were selected and divided into 10 fragments, named enhx(x=1,2,3,…10). Every fragment was 1 200 bp long, and 200 bp was repeated between two adjacent fragments. Above 10 fragments and the enhancer sequence of simian virus 40 (SV40) were amplified and inserted into the plasmid pEGFP-MU to construct the recombinant plasmid pEGFP-MU-enhx and pEGFP-MU-SV40e. The plasmids were then transfected into hepatoma carcinoma cells BEL-7402 and gastric carcinoma cells SGC-7901 using liposomes 2000. The effects of above candidate sequences on the transcription activity of cytomegalo virus promoter were detected using fluorescence microscope and flow cytometry. Results: Electrophoresis and DNA sequencing demons-trated that cloned target fragments(enh1-enh10 and SV40 enhancer) were completely accordant with the sequences registered in GeneBank. The restriction enzyme digestion and sequencing showed that recombinant plasmids pEGFP-MU-enhx and pEGFP-MU-SV40e fit the bill of experiment. After transient transfection,fluorescence microscope and flow cytometer found that the expressions of recombinant plasmids pEGFP-MU-enh6, pEGFP-MU-enh7 and pEGFP-MU-enh8 in the tumor cells BEL-7402 and SGC-7901 were increased and similar with that of positive control pEGFP-MU-SV40e, and that the expressions of other recombinant plasmids were relatively decreased. Conclusion: The 10 candidate DNA fragments of human HPSE gene enhancer are successfully cloned, and the recombinant plasmids pEGFP-MU-enhx are correctly constructed. The 6-8th candidate DNA fragments could possess the activity of enhancer. It zooms out the search scope for further screening and identifying active enhancer, and the study provides experimental evidence for future gene therapy using HPSE enhancer.