Band 3 membrane domain were expressed on yeast membrane surface by pYD1 yeast display system. The expressed membrane domain showed anion transport activity and DIDS could inhibit this function of membrane domain. About 1 500 bp cDNA fragment of truncation mutagenesis of band 3 membrane domain were amplified by PCR, which knockout Ala908～Val911, Asp896～Val911, Lys892～Val911 and Asn880～Val911 of band 3 respectively. After being sequenced, the four gene fragments cloned into EcoRⅠ～BamHⅠ sites of pYD1. The recombinant plasmids pYD1-Trunc4/Trunc16/Trunc20/Trunc32 were transformed into yeast EBY100. As control, pYD1-mdb3 was also transformed. After four groups fusion protein were expressed after adding galactose, the Cl^- transport activity was measured by using a fluorescent probe SPQ. The result demonstrated that the transport activity of band 3 was decreased when knockout Lys892～Val911 of AE1-C-terminal domain, but the transport activity didn't decrease further when knockout Asn880～Val911 of AE1-C-terminal domain. These results showed that Lys892～Phe895 amino acids influenced the anion transport of band 3 transmembrane domain.