Hf<inf>0.5</inf>Zr<inf>0.5</inf>O<inf>2</inf> (HZO) — based flexible RRAM was fabricated by low-temperature atomic layer deposition (ALD) process. The resistive switching (RS) characteristics were improved by the stacked structure (Ag/HZO/Al<inf>2</inf>O<inf>3</inf>/ITO/PET). ON/OFF ratio was increased from 10<sup>2</sup> to 10<sup>6</sup> and the values of the set voltage (from 0.5∼2.5V to 0.1∼1V) and reset voltage (from −0.8∼-2V to −0.1∼-0.8V) were reduced and more uniform, which should be linked to the regulation of added Al<inf>2</inf>O<inf>3</inf> film. This study provides a promising candidate for flexible memory devices and wearable electronics.