An RRAM structure includes a substrate. The substrate is divided into a memory cell region and a logic device region. A metal plug is disposed within the memory cell region. An RRAM is disposed on and contacts the metal plug. The RRAM includes a top electrode, a variable resistive layer, and a bottom electrode. The variable resistive layer is disposed between the top electrode and the bottom electrode. The variable resistive layer includes a first bottom surface. The bottom electrode includes a first top surface. The first bottom surface and the first top surface are coplanar. The first bottom surface only overlaps and contacts part of the first top surface.