A new method was introduced in order to improve accuracy of color matching by using the Kubelka-Munk theory. In the color matching calculation, experimental spectral reflection data of mixed colorants were adopted with those of originals, and both separated scattering coefficients and absorption coefficients derived from the K/S value were taken into consideration. The spectral color matching calculation was carried out with a weight value at each wavelength. Satisfactory results were obtained in the calculation for the color samples specified in Japan Industrial Standards for Color Rendering Properties (JIS-Z-8726). Advantages of this method are that the calculated result is fairly coincident with the sample data obtained experimentally from the calculated mixing ratio, and that the matched data have wide rendering tendency for different color tempera tures of light sources.