In an optical property measuring method and an optical property measuring apparatus, a spectral transmittance characteristic of a reference colored layer prepared as a reference is corrected based on a measured spectral reflection characteristic of a colored layer, and the spectral reflection characteristic of the reference colored layer. With this arrangement, information on the measured spectral transmittance characteristic of the colored layer can be obtained with sufficient precision in conformity with a printing condition of a sample to be measured. Thus, colorimetry of a printed color of a fluorescent sample i.e. a colored surface on a fluorescent substrate can be accurately performed by using the corrected spectral transmittance characteristic of the reference colored layer.