Provided is a thermosensitive recording medium having a sufficient water resistance to moisture and humidity, such as for outdoor use in rainy weather and the like, and also having a superior color developing sensitivity, print image quality when printing at high speed, ink fixability and solvent resistance and the like. As the protective layer comprises a specific silane-modified acrylic resin which is an aqueous emulsion of core-shell type p articles, in a thermosensitive recording medium having a thermosensitive recording layer on a substrate and a protective layer on the thermosensitive recording layer, the thermosensitive re cording medium has a sufficient water resistance and also has a superior color developing sensitivity, print image quality when printing at high speed, ink fixability and solvent resistance and the like.