Durability of dyes in thermal dye transfer printing images was improved by developing the Over Protect Layer(OP layer) and optimizing printing conditions. In this report, the relation between image durability and the condition of the transferred dyes in the dye receiving layer is studied. As for the thermal dye transfer printing image, the durability of the dye itself is important, even the interaction between the dyes and the dye receiving layer materials is important. The transferred dyes exist in the surface of the dye receiving layer in the dye receiving sheet. It is understood that dyes diffuse toward the depth of the dye receiving layer by thermal transferring the OP layer. It is conceivable that the dyes that exist in the molecule state in the dye receiving layer are strong in terms of durability. The UV(ultraviolet) rays absorbents that are included in the OP layer, have accomplished the role that prevents the dye deterioration.