Determination of correction factor of Yule-Nielsen spectral neugebauer (YNSN) model is a difficult problem. The reciprocal of paper's spectral reflectance was applied as the correction factor of Yule-Nielsen spectral neugebauer model to reduce the error between calculated and practical dot area rate. The result showed that the modified YNSN mode can be used to calculate the effective dot area rate. The purpose was to provide reference for controlling and testing printing color.