Abstract: A resistive random access memory (RRAM)-based hybrid physical unclonable function (PUF) for chip fingerprint is described in this paper. The “E” shape central symmetrical RRAM uses graphene thin film as electrode layer, and has wide distribution of resistance and high on-off resistance ratio; the resistance variation of RRAM is introduced to PUF cell as an entropy source to improve the uniqueness of PUFs; the different resistance states of RRAM are used to amplify initial deviation of PUF cell and improve the stability of PUFs; the cycle-to-cycle variation of RRAM is utilized to reconstruct the chip ID and improve the security of PUFs. The proposed PUF is designed in a 0.35μm CMOS technology. Simulation results show that the proposed PUF has good characteristics of uniqueness and stability, the inter-chip hamming distance (HD) in normal conditions is 49.95%, and the bit error rate is zero when temperature varies from −40 ℃ to 100 ℃, and supply voltage changes from 4.6 V to 5.4 V.