The present invention relates to a developer mixture for a thermal recording material, which comprises a mixture of the first organic developer comprising a condensate or a condensed composition represented by the formula (I): wherein R is a lower alkyl group or an aralkyl group, n is an integer of 0 to 5, and X and Y are each a hydrogen atom, an alkyl group or an aryl group, and the second organic developer other than the first organic developer (except 2,2-bis(3-methyl-4-hydroxyphenyl)propane), a developer mixture for a thermal recording material, and a thermal recording material having a heat-coloring layer containing the developer mixture. Using the developer mixture for a thermal recording material of the present invention, a thermal recording material sufficiently satisfying the recent requirement for high sensitivity, and having superior preservation stability of color images and non-image areas can be realized.