Objective:To clone and express the full length cDNA of human CD38. Methods:The full length cDNA of the human CD38 antigen was amplified from total RNA of Daudi cell by RT-PCR, and it was inserted into pGEM-T. The validity on the sequences was confirmed by automatic DNA sequencing. Inserting the valid CD38 gene into pcDNA3.1(+) plasmid to obtain recombinant mammalian expression vector pcDNA3.1(+)/CD38Z; Using lipofectin gene transfer technique system, recombinant expression vector containing CD38 gene was transfected into COS7 cells. The expression of CD38 molecules on the surface of COS7 cells was detected by FACS and immunohistochemical technique. Results:DNA sequencing showed that the cloned full length cDNA sequence was identical with reported. The result of FACS and immunohistochemical technique indicated that CD38 molecules were expressed on the surface of COS7 cells. Conclusion:The full length cDNA of human CD38 is obtained, recombinant mammalian expression vector pcDNA3.1(+)/CD38Z is successfully constructed, and the CD38 molecules is expressed on the surface of COS7 cells,this may facilitate studies on the biochemistry and function of CD38 antigen.