PURPOSE: To enhance an absorption in a near infrared region and to improve a surface whiteness and an image-positional stability, by incorporating a colorless or light-colored specific leuco dye and a specific color developer coloring the leuco dye under heat application.

CONSTITUTION: In a thermal recording material containing a colorless or light- colored leuco dye and a color developer coloring the leuco dye under heat application, the leuco dye uses at least one of monovinyl phthalide compounds shown by a formula (I), where R1 and R2 represent 1W6 C straight-chain or branched alkyl group or cycloalkyl group, R3 represents hydrogen atom, alkyl group, or alkoxy group, and R4 represents hydrogen atom or a group (a). The color developer uses a material composed of at least one of phenol compounds shown by formulas (II) where R5, R6, R7, and R8 represent 1W4 C straight-chain or branched alkyl, (III) where R9 represents alkyl or aralkyl, and (IV). In this manner, a material sufficiently practical as a near infrared absorption thermal recording material can be obtained with a remarkably superior surface whiteness after the storage under high-temperature and high-humidity conditions as well as in an initial state.