The effect of press-drying temperature on the surface chemistry of chimicothernomechanical pulp fibers has been studied using electron spectroscopy for chemical analysis (ESCA). The chemical composition showed no significant variation for press-dried samples at temperatures between 25 and 140 degrees C. On the other hand, ESCA showed that lignin content increased whereas hemicelluloses content decreased on the surface of press-dried samples at 175 degrees C. By its hydrophobic nature, lignin gives to paper and paperboards better dimensional stability and resistance to moisture and water. However, lignin does not intervene in fiber bonding because the specific bond strength does not vary with press-drying temperature.