This paper is concerned with the improvement of the combined properties of a phenolic resin-based thermal imaging composition. A surfactant-like additive, stearamide, was introduced to the imaging material. When drying, the surfactanct material will move to the surface of the thermo-sensitive film to form a very thin layer due to the low surface energy. The thin layer was the so-called monolayer. It can be broken by the infrared laser and developed together with the resin of the exposed area. However, the unexposed area will be protected by this thin layer. As a result, the difference between the exposed area and unexposed area became larger, and the image tolerance and image quality were improved.