This article investigates the carrier transport phenomenon and multilevel switching mechanism of Cr2 O3 -based resistive random access memory (RRAM) with Pt/ Cr2 O3 /TiN structure. Before the forming process, the interfacial Schottky barrier dominates the carrier transport. The barrier heights of Pt/ Cr2 O3 and Cr2 O3 /TiN are 0.7 and 0.96 eV, respectively. After the forming process, RRAM at a low resistance state follows the Ohmic conduction. While RRAM is switched to a high resistance state during the reset process, the Frenkel-Poole emission becomes a dominant conduction mechanism. The multilevel resistance states were achieved by applying corresponding reset voltages to the device for controlling the trap levels of the Cr2 O3 layer.