The binding processes of Reactive Red K-2BP (K-2BP) and Reactive Violet K-3R (K-3R) onto poly(epicholorohydrin-diamine)(PEPIDA) in solution and film were investigated by spectrophotometric and quartz crystal microbalance (QCM) methods, respectively. By using a multiple linear regression technique, the concentrations of the colored components in the mixtures of dye + PEPIDA were measured simultaneously from the absorbance spectra. The binding equilibrium constants for K-3R and K-2BP onto PEPIDA in solution were estimated to be 9.31 x 10(6) and 1.86 x 10(6) L.mol(-1), respectively. The difference in the color removal between K-3R and K-2BP by PEPIDA was discussed. The binding processes of K-3R and K-2BP onto PEPIDA film were followed by the QCM. The binding equilibrium constants were evaluated to be 1.27 x 10(6) and 3.28 x 10(5) L.mol(-1) for K-3R and K-2BP onto PEPIDA film, respectively. They are less than those determined in PEPIDA solutions. The binding rate constants for K-3R and K-2BP onto PEPIDA film were estimated to be 1.43 x 10(5) and 1.72 x 10(5) L.mol(-1).s(-1), respectively.