Phage display antibody library is an important technology for generating therapeutic antibody.It was reported that the construction and characterization of a large human antibody phage display library.Total RNA was extracted from peripheral blood lymphocytes of 20 healthy donors.VH and VL gene were amplified by RT-PCR.The ScFv(single chain variable fragment)gene were assembled by overlap PCR,and cloned into a phagemid vector by electroporation of E.coli TG1.A large nave human ScFv phage antibody library containing 1.3×109 antibody members was constructed by repetitive electroporation about 300 times.The quality of the library was examined by sequence analysis and selection against 5 different protein antigens.Sequence analysis of the randomly picked 40 clones showed this library had good diversity.Panning of the 5 different antigens all resulted in successful isolation of antigen specific ScFv antibodies.The results indicate that a large nave human ScFv phage antibody library with good diversity was constructed successfully.