A reversible thermosensitive recording medium having a supporting substrate
and a reversible thermosensitive recording layer formed on the supporting
substrate, being capable of reversibly varying color density depending
upon temperature with improved durability, is provided. The recording
medium has the rates of changes in recording sensitivity and in erasure
sensitivity, which are caused by the immersion in an artificial
perspiration liquid, of 50% or less and 80% or more, respectively, and an
average maximum particle size of organic materials of 2.5 microns at most.