PURPOSE: To obtain a donor element for use in a thermal transfer process comprising a support having on one side thereof a thermally transferable fluorescent heterocyclic compound dispersed in a polymeric binder wherein the fluorescent compound has a specified structure exhibiting a solubility good for organic solvent generally regarded as harmless to the environment.

CONSTITUTION: In a donor element for use in a thermal transfer process comprising a support having on one side thereof a thermally transferable fluorescent heterocyclic compound dispersed in a polymeric binder, the fluorescent compound corresponds to one of formulas I or II, wherein: R1represents a hydrocarbon group or a substituted hydrocarbon group; R2 represents hydrogen, a hydrocarbon group, a substituted hydrocarbon group, a carboxylic acid group, an ester group, a nitro group, a carbamoly group, a substituted carbamoly group, an amino group or a substituted amino group; R3 represents hydrogen, a hydrocarbon group, a substituted hydrocarbon group, a carboxylic acid group, an ester group, a carbamoly group or a substituted carbamoly group; R4 represents hydrogen or a hydrocarbon group or a substituted hydrocarbon group; X represents an electronegative substituent; and Z represents a quinoline nucleus, or the like.