Abstract: Objective To clone DNA sequence of human telomerase reverse transcriptase promoter(hTERTp) and to explore the function of the promoter in promoting enhanced green flurescence protein(EGFP) and the relationship between promoter length and function.Methods The hTERT promoter of 2068bp,1 135 bp,333bp,142bp were amplified.The hTERT promoters were inserted into upstream of EGFP to reconstruct four recom binant plasmids and transfected into the SW 579 cells.Then the fluo rescence intensity was detected and the promoter rate was identified.Results The promote effiency of four eukaryotic plasmids decreased with the shortening of the promoter length with the fluoreslenic intensity of 8.56,7.81,6.88 and 3.62 from high to low.Conclusion The human telomerase reverse transcriptase expression and activity change are correlated with the length of the promoter.The research gives away for tumorgene therapy by down regulation of the acitivity of hTERTp.