A resistive random access memory is provided. The resistive random access memory includes a bottom electrode over a substrate, a top electrode, a resistance-switching layer, an oxygen exchange layer, and a sidewall protective layer. The top electrode is disposed over the bottom electrode. The resistance-switching layer is disposed between the bottom electrode and the top electrode. The oxygen exchange layer is disposed between the resistance-switching layer and the top electrode. The sidewall protective layer containing metal or semiconductor is disposed at sidewalls of the resistance-switching layer, and the sidewalls of the resistance-switching layer is doped with the metal or semiconductor from the sidewall protective layer.