A bacteriophage T7 display vector for expressing and displaying an exogenous peptide, wherein the display vector comprises a polynucleotide encoding a bacteriophage T7 tail fiber protein p17 in which a hepatocyte-targeting determinant sequence is inactivated, and wherein a cloning site is contained in a coding sequence for the tail fiber protein p17 or in a coding sequence for a capsid protein p10B. Also provided are a host cell containing the display vector as described above, a bacteriophage T7 particle comprising at least one copy of a p17 protein which comprises an exogenous peptide displayed thereon, or at least one copy of a p10 protein with an exogenous peptide displayed thereon, wherein a hepatocyte-targeting determinant sequence on the bacteriophage T7 tail fiber protein p17 is inactivated. The present invention further provides a viral lysate containing assembled bacteriophage T7 particle described above, and a method for determining if a candidate peptide is a liver-targeting peptide, or for screening for liver targeting peptides.