A resistive random access memory (RRAM) structure includes a substrate. A transistor is disposed on the substrate. The transistor includes a gate structure, a source and a drain. A drain contact plug contacts the drain. A metal interlayer dielectric layer is disposed on the drain contact plug. An RRAM is disposed on the drain and within a first trench in the metal interlayer dielectric layer. The RRAM includes the drain contact plug, a metal oxide layer and a top electrode. The drain contact plug serves as a bottom electrode of the RRAM. The metal oxide layer contacts the drain contact plug. The top electrode contacts the metal oxide layer and a metal layer is disposed within the first trench.