The present invention relates to a reducing or non-reducing polynucleotide polymer for drug delivery and a method for preparing same, and provides a reducing or non-reducing polymer synthesized by using nucleotides, a method for preparing same, and a polymer composition for drug delivery containing the reducing or non-reducing polymer. The present invention relates to a drug delivery carrier for delivering proteins or peptides to a targeted area through electrostatic attraction, by obtaining a negatively(-) charged polymer by using nucleotides to synthesize the reducing or non-reducing polymer, which is easily breakable due to disulfide bonds, and then bonding the negatively(-) charged polymer with a positively(+) charged protein or peptide, wherein a polymer derived from a non-viral drug delivery carrier containing the novel reducing or non-reducing polymer is capable of effectively enabling escape of a drug, delivered by means of proton buffering activity, from an endosome to other organelles in a cell.
