Phenolisatine polymers having high thermal stability were synthesized by condensation polymerization method and applied to a new thermosensitive recording media.Recording composition was prepared by mixing the polymer with a leuco dye and a coupler. The resultant recording composition showed excellent hue and provided sufficient density of formed color up to 250°C as compared to the recording composition without phenolisatine polymers. Thermally erasable recording composition was prepared by adding a decolorant into above recording media containing phenolisatine polymers. The resultant recording media showed no loss of color up 170°C but visibly bleached at above 200°C, indicating potential use of the composition as a thermosensitive recording media. Effect of the composition of the recording media on the thermosensitivity will be presented.