Abstract: In this paper nanoscale Hf /HfO₂-based resistive random-access-memory（ RRAM） devices were fabricated. The cross-over between top electrode and bottom electrode of RRAM forms the metal-oxide-metal sandwich structure. The electrical responses of RRAM are systematically studied,including forming process,SET process and RESET process. The correlations between SET voltage and RESET voltage,high resistance state and low resistance state are discussed. The electrical characteristics of RRAM are in strong relationship with compliance current in SET process. The conduction mechanism of nanoscale Hf /HfO₂-based RRAM can be explained by quantum point contact model.