Aim To select the functional domain of Daxx which can interact with androgen receptor(AR). Methods Four functional domains of Daxx were amplified by polymerase chain reaction(PCR) and subcloned to a prokaryotic expression vector(pGEX-6p-1) respectively.The recombinant DNA fragments were identified by DNA sequencing.All recombinant vectors were stably transformed into E Coli.BL21DE3 and induced by IPTG.Four recombinant peptides were detected to interact with AR by using GST pull-down in vitro,respectively. Results The results of pGEX-6p-1/Daxx/DM1-240,pGEX-6p-1/Daxx/DM241-501,pGEX-6p-1/Daxx/DM502-625 and pGEX-6p-1/Daxx/DM626-740 from DNA sequencing indicates that there is no reading frame shifts and mutations in recombinant.The protein expressed from pGEX-6p-1/Daxx/DM626-740 can interact with AR by using GST pull-down in vitro. Conclusion The 626th to 740th in amino acid of Daxx can combine AR.