A method was developed for predicting the productivity P (amount of the target protein recovered per unit volume per unit time) of affinity chromatography (AFC) and similar chromatographic operations. The constant-pattern approach was employed for describing the breakthrough curve. It was found that P increases with increasing u at low u regions and there is a maximum in the P-u curve. The u value that gives the maximum P (uM) was derived as a function of the number of transfer units, n. The experimental breakthrough curves for several different packing media systems such as 40- and 10-microns porous particles, 2.5-microns non-porous particles and surface-derivatized membrane media were measured, from which the n values were determined. The uM values were then calculated using the n values. It is suggested that the present method is useful for the rapid survey of the operating conditions in scaling-up AFC and similar chromatographic operations.