The photo-thermal stability and tribological properties of Zdol lubricant, modified by substituting the OH groups with benzophenone, were investigated under laser beam exposure. The change of reflectance of the modified Zdol lubricant films induced by laser beam exposure was measured using a surface reflectance analyzer (SRA). The friction force of modified Zdol lubricant films was measured at the interface between a slider and a disk on a spin stand. Modified Zdol films show less reflectance change than pure Zdol. The photo-thermal stability under laser beam exposure increases with an increase of the substitution ratio. Reflectance change occurs due to depletion of the lubricant and/or modification of the lubricant optical properties under laser beam exposure. Unlike pure Zdol, the normalized friction force of modified Zdol remains constant under laser beam exposure. Modified Zdol lubricants are potential disk lubricants for heat-assisted magnetic recording applications.