In this paper, the HfO2-based resistive switching memory (RRAM) using carbon nanotubes (CNTs) as contact electrodes for high density integration is demonstrated. The Al/ HfO2/CNTs devices show self-compliance, forming-free and low resistive state (LRS) nonlinearity with less than 130 nA reset current (I-reset). By contrast with the Al/ HfO2/Ti devices, resistive switching behavior has been enhanced significantly by using CNTs electrode. For the Al/ HfO2/CNTs devices, current-voltage (I-V) characteristics demonstrate that the current conduction in high resistive state (HRS) and low resistive state (LRS) is controlled by space-charge-limited current (SCLC) and trap-controlled SCLC mechanism, respectively. (C) 2017 Elsevier Ltd. All rights reserved.