Objective To find a rapid and simple method for quantifying the amount of eluted proteins in chromatography. Methods The method was developed by utilizing the principle of the absorbance of protein at 280 nm and the integral function of the software UNICORN for AKTA FPLC, namely, the protein quantity was evaluated based on its A_ 280 and peak area. Results The relation between peak area and quantity of the protein was linear correlation. The protein quantity could be expressed as X=Y/A. The Y represented the peak area (mAU?ml) of the interested fraction, and A represented the measurable value (mAU) of 1 g/L interested protein through the FPLC 280 nm cell and X was the quantity of the interested protein (mg). The method was used in the purification of recombinant human zona pellucida-3 protein (rhZP3)and the quantity of the purified rhZP3 evaluated from the formula was confirmed by Lowry method. Conclusion The method is easy, rapid, repeatable and practicable to quantify the protein in chromatography.