By controlling the amorphous-to-crystalline relative volume,chalcogenide phase-change memory mate-rials can provide multi-level data storage (MLS),which offers great potential for high-density storage-class memory and neuro-inspired computing.However,this type of MLS system suffers from high power consumption and a severe time-dependent resistance increase (“drift”) in the amorphous phase,which limits the number of attainable storage levels.Here,we report a new type of MLS system in yttrium-doped antimony telluride,utilizing reversible multi-level phase transitions between three states,i.e.,amorphous,metastable cubic and stable hexagonal crystalline phases,with ultralow power consumption(0.6-4.3 pJ) and ultralow resistance drift for the lower two states (power-law exponent ＜ 0.007).The metastable cubic phase is stabilized by yttrium,while the evident reversible cubic-to-hexagonal transi-tion is attributed to the sequential and directional migration of Sb atoms.Finally,the decreased heat dis-sipation of the material and the increase in crystallinity contribute to the overall high performance.This study opens a new way to achieve advanced multi-level phase-change memory without the need for complicated manufacturing procedures or iterative programming operations.