A novel True Random Number Generator (TRNG) based on analog RRAM is developed. For the first time, the proposed TRNG harvests the variation of the pulse number in programming the analog states as the random source, and utilizes the parity of the pulse number to generate random bits. The TRNG throughput reaches >1 Mbit/sec for a single cell. The feasibility for chip-level parallel operation on multiple cells is verified experimentally to further improve the throughput. Excellent stability against temperature variation is also demonstrated. All the generated random bit streams pass the NIST tests across –40 to 125 °C. With an optimized small analog switching window, the endurance problem is significantly relieved as the functionality of TRNG is retained after 1011 incremental switching cycles. Our high-speed and high-reliability TRNG design is compatible with the existing memory block and convenient for circuit implementation, making it suitable for future IoT applications.