Peptides having activity of inhibiting infections of respiratory viruses, use of the same and methods of preparing the same are disclosed. The peptides can be synthesized by chemical or genetic engineering methods, and they have functional domain capable of binding to surface glycoprotein of respiratory viruses and activity of inhibiting infections of respiratory viruses. The peptides are useful for blocking infections of respiratory viruses in target cells, for prevention/treatment of said infections, and for development of new prophylactic/therapeutic medicaments against respiratory viruses. Also disclosed are isolated DNA encoding any of the peptides, expression vector comprising the DNA operatively linked to a promoter, host cell comprising the expression vector, and a kit for screening peptide capable of inhibiting said infections and the screening method. The invention also discloses the mechanism of the peptides in inhibition of said infections, which provides theory support for developing new prophylactic/therapeutic agents with broad-spectrum antiviral activities.