Objective:This study aims to construct the promoter of human cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)gene,and explore its promoter activity and transcriptional regulation mechanism. Methods:The 1 254 bp(-1 178~+76 bp)fragment of 5′ upstream of human cGAS gene was amplified by PCR and subcloned into pGL3-basic plasmid. By a series of 5′ deletion and promoter constructions,the core region of cGAS promoter was founded. Luciferase assays were used to detect the activity of recombinant plasmids in Hela cells. Then,the transcription factor binding sites in promoter region were predicted by bioinformatics. Finally,potential transcription factor binding sites were verified by point mutation experiments. Resluts:The luciferase reporter gene recombinant plasmids of cGAS gene promoter were successfully constructed. In comparison with the pGL3-basic plasmid,the relative luciferase activities of recombinant palsmids of cGAS promoter were much higher(P < 0.05). What’s more,bioinformatics software predicts that the proximal promoter region of human cGAS(-414~+76 bp) may contain binding sites of transcription factors such as Sp1,CREB,USF1,RAP1,C-JUN and OCT-1. Sp1 and CREB positively regulated promoter region,which was confirmed by point mutation experiment. Conclusion:It is concluded that the proximal promoter core region of human cGAS has strong promoter activity,which contains many potential transcription factors binding sites. The transcription factor Sp1 and CREB regulates the human cGAS promoter region.