A novel experimental method is described that allows the determination of surface-state capture cross section for minority carriers and the calculation of surface-state densities from transfer-loss measurements in surface channel CCD's. Using two-level polysilicon two-phase n-channel CCD's, σn(E) was found to vary between about 5×10-17 and 2×10-16 cm2, and Nss(E) between 1.7×1011 and 9×109 cm-2 eV -1 in an energy range of 0.05 to 0.42 eV below the conduction-band edge.