This invention provides a reversibly thermochromic ultraviolet ray-hardening type ink having good color change sensitivity and excellent light resistance and fastness, and a reversibly thermochromic laminate produced using the same. The present invention also provides a reversibly thermochromic laminate produced by forming a reversibly thermochromic layer on a support using the same. The ink comprises: (1) a microencapsulated pigment comprising a reversibly thermochromic composition comprising (A) an electron-donating compound, (B) an electron-accepting compound and (C) a color change temperature-controlling agent which controls color reaction generation temperature of the former two compounds; and (D) a light resistance-providing agent represented by a specific formula, and (2) a photo-polymerizable composition comprising an ultraviolet ray absorbent, a reactive oligomer, a reactive monomer, and an acylphosphine oxide photo-polymerization initiator, wherein said microencapsulated pigment is dispersed in said photo-polymerizable composition.