A novel vertical RRAM for 3D cross-point architecture is proposed. The design and optimization issues of the proposed vertical RRAM for 3D cross-point architecture array are addressed from both device and array levels. A double layer stacked HfOx based vertical RRAM devices with interface engineering fabricated using a cost-effective fabrication process. The excellent performances such as low reset current, fast switching speed, high switching endurance and disturbance immunity, good retention and self-selectivity are demonstrated in the fabricated HfOx based vertical RRAM devices. The opimized design guidances for the 3D cross-point architecture array are presented.