Double-stranded DNA was used as a molecular wire to enhance the electron transfer reaction between PEO-modified myoglobin (PEO-Mb) and electrode in PEO oligomers. No acceleration but suppression of electron transfer was found when only DNA was used. The π stacking of base-pairs in DNA was enhanced by the complexation with bisbenzimide. Larger current of PEO-Mb was found under suitable values of the molar ratio of bisbenzimide to DNA base pair, the quantity of cast PEO-Mb, and the ratio of DNA base pair to PEO-Mb. DNA/bisbenzimide complex was revealed to be effective for the electron transfer reaction between heme-proteins and electrode even in ion conductive polymer matrix.