A three-dimensional dynamic random access memory with an ancillary electrode structure includes a substrate, at least one bit line formed on the substrate, at least one pillar element formed on a growth zone of the bit line, an ancillary electrode, a character line parallel with the substrate and perpendicular to the bit line, and at least one capacitor connecting to the pillar element. The bit line is formed on the substrate by doping and diffusing a doping element. The ancillary electrode is located on a separation zone of the bit line and adjacent to the pillar element. The character line is insulated from the ancillary electrode and incorporates with the bit line to output or input electronic data to the capacitor. Through the ancillary electrode, impedance of the bit line can be controlled to enhance conductivity of the bit line.