The present paper describes a method for modeling human skin coloring and estimating the surface-spectral reflectance by using the Kubelka-Munk theory. First, human skin is modeled as two layers of turbid materials. Second, we describe the reflectance estimation problem as the Kubelka-Munk equations with unknown six parameters. These parameters are the regular reflectance at skin surface and the five weights for spectral absorption of such different pigments as melanin, carotene, oxy-hemoglobin, deoxy-hemoglobin, and bilirubin. Moreover, the optical coefficients of spectral absorption and scattering for the two skin layers and the thickness values of these layers are used for the solution. Finally, experiments are done for estimating the skin surface-spectral reflectance on some body parts, such as the cheeks of human face, the palm, the backs of hand, the inside of arm, and the outside of arm. It is confirmed that the proposed method is more reliable in all cases.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.