PURPOSE: To form and erase an image with excellent contrast by using specific compound as electron acceptive compound, and further incorporating at least one of three types of specific compounds as a color erasing accelerator.

CONSTITUTION: A compound represented by a formula I is used as electron acceptive compound which creates reversible color tone change due to the difference of cooling velocity after heating at a dye precursor which is normally colorless or pale. Further, at least one type from compounds represented by formulae II, III and IV are incorporated as a color erasing accelerator, where in the formulae I to IV, X is O or S, Y is bivalent group having -COHN bond, A is a complex ring having one or more of N atoms, B is amino compound having one or more of N atoms, R is CH group having several tens to 24 of C, Ra, Rc and Re are 1-12C CH2 group, Rb and Rf are 1-24C CH group, Rd is 1-24C CH group having one S, n and p are 1 to 3, m is 0 to 3, and h, i, j and k are 0 or 1, of integer respectively. Thus, erasability can be improved.